text: /*
     Copyright (C) 2002 Richard Henderson
     Copyright (C) 2001 Rusty Russell, 2002, 2010 Rusty Russell IBM.
  
      This program is free software; you can redistribute it and/or modify
      it under the terms of the GNU General Public License as published by
      the Free Software Foundation; either version 2 of the License, or
      (at your option) any later version.
  
      This program is distributed in the hope that it will be useful,
      but WITHOUT ANY WARRANTY; without even the implied warranty of
      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
      GNU General Public License for more details.
  
      You should have received a copy of the GNU General Public License
      along with this program; if not, write to the Free Software
      Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  */
  #include <linux/module.h>
  #include <linux/moduleloader.h>
  #include <linux/ftrace_event.h>
  #include <linux/init.h>
  #include <linux/kallsyms.h>
  #include <linux/fs.h>
  #include <linux/sysfs.h>
  #include <linux/kernel.h>
  #include <linux/slab.h>
  #include <linux/vmalloc.h>
  #include <linux/elf.h>
  #include <linux/proc_fs.h>
  #include <linux/seq_file.h>
  #include <linux/syscalls.h>
  #include <linux/fcntl.h>
  #include <linux/rcupdate.h>
  #include <linux/capability.h>
  #include <linux/cpu.h>
  #include <linux/moduleparam.h>
  #include <linux/errno.h>
  #include <linux/err.h>
  #include <linux/vermagic.h>
  #include <linux/notifier.h>
  #include <linux/sched.h>
  #include <linux/stop_machine.h>
  #include <linux/device.h>
  #include <linux/string.h>
  #include <linux/mutex.h>
  #include <linux/rculist.h>
  #include <asm/uaccess.h>
  #include <asm/cacheflush.h>
  #include <asm/mmu_context.h>
  #include <linux/license.h>
  #include <asm/sections.h>
  #include <linux/tracepoint.h>
  #include <linux/ftrace.h>
  #include <linux/async.h>
  #include <linux/percpu.h>
  #include <linux/kmemleak.h>
  #include <linux/jump_label.h>
  #include <linux/pfn.h>
  #include <linux/bsearch.h>
  
  #define CREATE_TRACE_POINTS
  #include <trace/events/module.h>
  
  #if 0
  #define DEBUGP printk
  #else
  #define DEBUGP(fmt , a...)
  #endif
  
  #ifndef ARCH_SHF_SMALL
  #define ARCH_SHF_SMALL 0
  #endif
  
  /*
   * Modules' sections will be aligned on page boundaries
   * to ensure complete separation of code and data, but
   * only when CONFIG_DEBUG_SET_MODULE_RONX=y
   */
  #ifdef CONFIG_DEBUG_SET_MODULE_RONX
  # define debug_align(X) ALIGN(X, PAGE_SIZE)
  #else
  # define debug_align(X) (X)
  #endif
  
  /*
   * Given BASE and SIZE this macro calculates the number of pages the
   * memory regions occupies
   */
  #define MOD_NUMBER_OF_PAGES(BASE, SIZE) (((SIZE) > 0) ?		\
  		(PFN_DOWN((unsigned long)(BASE) + (SIZE) - 1) -	\
  			 PFN_DOWN((unsigned long)BASE) + 1)	\
  		: (0UL))
  
  /* If this is set, the section belongs in the init part of the module */
  #define INIT_OFFSET_MASK (1UL << (BITS_PER_LONG-1))
  
  /*
   * Mutex protects:
   * 1) List of modules (also safely readable with preempt_disable),
   * 2) module_use links,
   * 3) module_addr_min/module_addr_max.
   * (delete uses stop_machine/add uses RCU list operations). */
  DEFINE_MUTEX(module_mutex);
  EXPORT_SYMBOL_GPL(module_mutex);
  static LIST_HEAD(modules);
  #ifdef CONFIG_KGDB_KDB
  struct list_head *kdb_modules = &modules; /* kdb needs the list of modules */
  #endif /* CONFIG_KGDB_KDB */
  
  
  /* Block module loading/unloading? */
  int modules_disabled = 0;
  
  /* Waiting for a module to finish initializing? */
  static DECLARE_WAIT_QUEUE_HEAD(module_wq);
  
  static BLOCKING_NOTIFIER_HEAD(module_notify_list);
  
  /* Bounds of module allocation, for speeding __module_address.
   * Protected by module_mutex. */
  static unsigned long module_addr_min = -1UL, module_addr_max = 0;
  
  int register_module_notifier(struct notifier_block * nb)
  {
  	return blocking_notifier_chain_register(&module_notify_list, nb);
  }
  EXPORT_SYMBOL(register_module_notifier);
  
  int unregister_module_notifier(struct notifier_block * nb)
  {
  	return blocking_notifier_chain_unregister(&module_notify_list, nb);
  }
  EXPORT_SYMBOL(unregister_module_notifier);
  
  struct load_info {
  	Elf_Ehdr *hdr;
  	unsigned long len;
  	Elf_Shdr *sechdrs;
  	char *secstrings, *strtab;
  	unsigned long symoffs, stroffs;
  	struct _ddebug *debug;
  	unsigned int num_debug;
  	struct {
  		unsigned int sym, str, mod, vers, info, pcpu;
  	} index;
  };
  
  /* We require a truly strong try_module_get(): 0 means failure due to
     ongoing or failed initialization etc. */
  static inline int strong_try_module_get(struct module *mod)
  {
  	if (mod && mod->state == MODULE_STATE_COMING)
  		return -EBUSY;
  	if (try_module_get(mod))
  		return 0;
  	else
  		return -ENOENT;
  }
  
  static inline void add_taint_module(struct module *mod, unsigned flag)
  {
  	add_taint(flag);
  	mod->taints |= (1U << flag);
  }
  
  /*
   * A thread that wants to hold a reference to a module only while it
   * is running can call this to safely exit.  nfsd and lockd use this.
   */
  void __module_put_and_exit(struct module *mod, long code)
  {
  	module_put(mod);
  	do_exit(code);
  }
  EXPORT_SYMBOL(__module_put_and_exit);
  
  /* Find a module section: 0 means not found. */
  static unsigned int find_sec(const struct load_info *info, const char *name)
  {
  	unsigned int i;
  
  	for (i = 1; i < info->hdr->e_shnum; i++) {
  		Elf_Shdr *shdr = &info->sechdrs[i];
  		/* Alloc bit cleared means "ignore it." */
  		if ((shdr->sh_flags & SHF_ALLOC)
  		    && strcmp(info->secstrings + shdr->sh_name, name) == 0)
  			return i;
  	}
  	return 0;
  }
  
  /* Find a module section, or NULL. */
  static void *section_addr(const struct load_info *info, const char *name)
  {
  	/* Section 0 has sh_addr 0. */
  	return (void *)info->sechdrs[find_sec(info, name)].sh_addr;
  }
  
  /* Find a module section, or NULL.  Fill in number of "objects" in section. */
  static void *section_objs(const struct load_info *info,
  			  const char *name,
  			  size_t object_size,
  			  unsigned int *num)
  {
  	unsigned int sec = find_sec(info, name);
  
  	/* Section 0 has sh_addr 0 and sh_size 0. */
  	*num = info->sechdrs[sec].sh_size / object_size;
  	return (void *)info->sechdrs[sec].sh_addr;
  }
  
  /* Provided by the linker */
  extern const struct kernel_symbol __start___ksymtab[];
  extern const struct kernel_symbol __stop___ksymtab[];
  extern const struct kernel_symbol __start___ksymtab_gpl[];
  extern const struct kernel_symbol __stop___ksymtab_gpl[];
  extern const struct kernel_symbol __start___ksymtab_gpl_future[];
  extern const struct kernel_symbol __stop___ksymtab_gpl_future[];
  extern const unsigned long __start___kcrctab[];
  extern const unsigned long __start___kcrctab_gpl[];
  extern const unsigned long __start___kcrctab_gpl_future[];
  #ifdef CONFIG_UNUSED_SYMBOLS
  extern const struct kernel_symbol __start___ksymtab_unused[];
  extern const struct kernel_symbol __stop___ksymtab_unused[];
  extern const struct kernel_symbol __start___ksymtab_unused_gpl[];
  extern const struct kernel_symbol __stop___ksymtab_unused_gpl[];
  extern const unsigned long __start___kcrctab_unused[];
  extern const unsigned long __start___kcrctab_unused_gpl[];
  #endif
  
  #ifndef CONFIG_MODVERSIONS
  #define symversion(base, idx) NULL
  #else
  #define symversion(base, idx) ((base != NULL) ? ((base) + (idx)) : NULL)
  #endif
  
  static bool each_symbol_in_section(const struct symsearch *arr,
  				   unsigned int arrsize,
  				   struct module *owner,
  				   bool (*fn)(const struct symsearch *syms,
  					      struct module *owner,
  					      void *data),
  				   void *data)
  {
  	unsigned int j;
  
  	for (j = 0; j < arrsize; j++) {
  		if (fn(&arr[j], owner, data))
  			return true;
  	}
  
  	return false;
  }
  
  /* Returns true as soon as fn returns true, otherwise false. */
  bool each_symbol_section(bool (*fn)(const struct symsearch *arr,
  				    struct module *owner,
  				    void *data),
  			 void *data)
  {
  	struct module *mod;
  	static const struct symsearch arr[] = {
  		{ __start___ksymtab, __stop___ksymtab, __start___kcrctab,
  		  NOT_GPL_ONLY, false },
  		{ __start___ksymtab_gpl, __stop___ksymtab_gpl,
  		  __start___kcrctab_gpl,
  		  GPL_ONLY, false },
  		{ __start___ksymtab_gpl_future, __stop___ksymtab_gpl_future,
  		  __start___kcrctab_gpl_future,
  		  WILL_BE_GPL_ONLY, false },
  #ifdef CONFIG_UNUSED_SYMBOLS
  		{ __start___ksymtab_unused, __stop___ksymtab_unused,
  		  __start___kcrctab_unused,
  		  NOT_GPL_ONLY, true },
  		{ __start___ksymtab_unused_gpl, __stop___ksymtab_unused_gpl,
  		  __start___kcrctab_unused_gpl,
  		  GPL_ONLY, true },
  #endif
  	};
  
  	if (each_symbol_in_section(arr, ARRAY_SIZE(arr), NULL, fn, data))
  		return true;
  
  	list_for_each_entry_rcu(mod, &modules, list) {
  		struct symsearch arr[] = {
  			{ mod->syms, mod->syms + mod->num_syms, mod->crcs,
  			  NOT_GPL_ONLY, false },
  			{ mod->gpl_syms, mod->gpl_syms + mod->num_gpl_syms,
  			  mod->gpl_crcs,
  			  GPL_ONLY, false },
  			{ mod->gpl_future_syms,
  			  mod->gpl_future_syms + mod->num_gpl_future_syms,
  			  mod->gpl_future_crcs,
  			  WILL_BE_GPL_ONLY, false },
  #ifdef CONFIG_UNUSED_SYMBOLS
  			{ mod->unused_syms,
  			  mod->unused_syms + mod->num_unused_syms,
  			  mod->unused_crcs,
  			  NOT_GPL_ONLY, true },
  			{ mod->unused_gpl_syms,
  			  mod->unused_gpl_syms + mod->num_unused_gpl_syms,
  			  mod->unused_gpl_crcs,
  			  GPL_ONLY, true },
  #endif
  		};
  
  		if (each_symbol_in_section(arr, ARRAY_SIZE(arr), mod, fn, data))
  			return true;
  	}
  	return false;
  }
  EXPORT_SYMBOL_GPL(each_symbol_section);
  
  struct find_symbol_arg {
  	/* Input */
  	const char *name;
  	bool gplok;
  	bool warn;
  
  	/* Output */
  	struct module *owner;
  	const unsigned long *crc;
  	const struct kernel_symbol *sym;
  };
  
  static bool check_symbol(const struct symsearch *syms,
  				 struct module *owner,
  				 unsigned int symnum, void *data)
  {
  	struct find_symbol_arg *fsa = data;
  
  	if (!fsa->gplok) {
  		if (syms->licence == GPL_ONLY)
  			return false;
  		if (syms->licence == WILL_BE_GPL_ONLY && fsa->warn) {
  			printk(KERN_WARNING "Symbol %s is being used "
  			       "by a non-GPL module, which will not "
  			       "be allowed in the future\n", fsa->name);
  			printk(KERN_WARNING "Please see the file "
  			       "Documentation/feature-removal-schedule.txt "
  			       "in the kernel source tree for more details.\n");
  		}
  	}
  
  #ifdef CONFIG_UNUSED_SYMBOLS
  	if (syms->unused && fsa->warn) {
  		printk(KERN_WARNING "Symbol %s is marked as UNUSED, "
  		       "however this module is using it.\n", fsa->name);
  		printk(KERN_WARNING
  		       "This symbol will go away in the future.\n");
  		printk(KERN_WARNING
  		       "Please evalute if this is the right api to use and if "
  		       "it really is, submit a report the linux kernel "
  		       "mailinglist together with submitting your code for "
  		       "inclusion.\n");
  	}
  #endif
  
  	fsa->owner = owner;
  	fsa->crc = symversion(syms->crcs, symnum);
  	fsa->sym = &syms->start[symnum];
  	return true;
  }
  
  static int cmp_name(const void *va, const void *vb)
  {
  	const char *a;
  	const struct kernel_symbol *b;
  	a = va; b = vb;
  	return strcmp(a, b->name);
  }
  
  static bool find_symbol_in_section(const struct symsearch *syms,
  				   struct module *owner,
  				   void *data)
  {
  	struct find_symbol_arg *fsa = data;
  	struct kernel_symbol *sym;
  
  	sym = bsearch(fsa->name, syms->start, syms->stop - syms->start,
  			sizeof(struct kernel_symbol), cmp_name);
  
  	if (sym != NULL && check_symbol(syms, owner, sym - syms->start, data))
  		return true;
  
  	return false;
  }
  
  /* Find a symbol and return it, along with, (optional) crc and
   * (optional) module which owns it.  Needs preempt disabled or module_mutex. */
  const struct kernel_symbol *find_symbol(const char *name,
  					struct module **owner,
  					const unsigned long **crc,
  					bool gplok,
  					bool warn)
  {
  	struct find_symbol_arg fsa;
  
  	fsa.name = name;
  	fsa.gplok = gplok;
  	fsa.warn = warn;
  
  	if (each_symbol_section(find_symbol_in_section, &fsa)) {
  		if (owner)
  			*owner = fsa.owner;
  		if (crc)
  			*crc = fsa.crc;
  		return fsa.sym;
  	}
  
  	DEBUGP("Failed to find symbol %s\n", name);
  	return NULL;
  }
  EXPORT_SYMBOL_GPL(find_symbol);
  
  /* Search for module by name: must hold module_mutex. */
  struct module *find_module(const char *name)
  {
  	struct module *mod;
  
  	list_for_each_entry(mod, &modules, list) {
  		if (strcmp(mod->name, name) == 0)
  			return mod;
  	}
  	return NULL;
  }
  EXPORT_SYMBOL_GPL(find_module);
  
  #ifdef CONFIG_SMP
  
  static inline void __percpu *mod_percpu(struct module *mod)
  {
  	return mod->percpu;
  }
  
  static int percpu_modalloc(struct module *mod,
  			   unsigned long size, unsigned long align)
  {
  	if (align > PAGE_SIZE) {
  		printk(KERN_WARNING "%s: per-cpu alignment %li > %li\n",
  		       mod->name, align, PAGE_SIZE);
  		align = PAGE_SIZE;
  	}
  
  	mod->percpu = __alloc_reserved_percpu(size, align);
  	if (!mod->percpu) {
  		printk(KERN_WARNING
  		       "%s: Could not allocate %lu bytes percpu data\n",
  		       mod->name, size);
  		return -ENOMEM;
  	}
  	mod->percpu_size = size;
  	return 0;
  }
  
  static void percpu_modfree(struct module *mod)
  {
  	free_percpu(mod->percpu);
  }
  
  static unsigned int find_pcpusec(struct load_info *info)
  {
  	return find_sec(info, ".data..percpu");
  }
  
  static void percpu_modcopy(struct module *mod,
  			   const void *from, unsigned long size)
  {
  	int cpu;
  
  	for_each_possible_cpu(cpu)
  		memcpy(per_cpu_ptr(mod->percpu, cpu), from, size);
  }
  
  /**
   * is_module_percpu_address - test whether address is from module static percpu
   * @addr: address to test
   *
   * Test whether @addr belongs to module static percpu area.
   *
   * RETURNS:
   * %true if @addr is from module static percpu area
   */
  bool is_module_percpu_address(unsigned long addr)
  {
  	struct module *mod;
  	unsigned int cpu;
  
  	preempt_disable();
  
  	list_for_each_entry_rcu(mod, &modules, list) {
  		if (!mod->percpu_size)
  			continue;
  		for_each_possible_cpu(cpu) {
  			void *start = per_cpu_ptr(mod->percpu, cpu);
  
  			if ((void *)addr >= start &&
  			    (void *)addr < start + mod->percpu_size) {
  				preempt_enable();
  				return true;
  			}
  		}
  	}
  
  	preempt_enable();
  	return false;
  }
  
  #else /* ... !CONFIG_SMP */
  
  static inline void __percpu *mod_percpu(struct module *mod)
  {
  	return NULL;
  }
  static inline int percpu_modalloc(struct module *mod,
  				  unsigned long size, unsigned long align)
  {
  	return -ENOMEM;
  }
  static inline void percpu_modfree(struct module *mod)
  {
  }
  static unsigned int find_pcpusec(struct load_info *info)
  {
  	return 0;
  }
  static inline void percpu_modcopy(struct module *mod,
  				  const void *from, unsigned long size)
  {
  	/* pcpusec should be 0, and size of that section should be 0. */
  	BUG_ON(size != 0);
  }
  bool is_module_percpu_address(unsigned long addr)
  {
  	return false;
  }
  
  #endif /* CONFIG_SMP */
  
  #define MODINFO_ATTR(field)	\
  static void setup_modinfo_##field(struct module *mod, const char *s)  \
  {                                                                     \
  	mod->field = kstrdup(s, GFP_KERNEL);                          \
  }                                                                     \
  static ssize_t show_modinfo_##field(struct module_attribute *mattr,   \
  	                struct module *mod, char *buffer)             \
  {                                                                     \
  	return sprintf(buffer, "%s\n", mod->field);                   \
  }                                                                     \
  static int modinfo_##field##_exists(struct module *mod)               \
  {                                                                     \
  	return mod->field != NULL;                                    \
  }                                                                     \
  static void free_modinfo_##field(struct module *mod)                  \
  {                                                                     \
  	kfree(mod->field);                                            \
  	mod->field = NULL;                                            \
  }                                                                     \
  static struct module_attribute modinfo_##field = {                    \
  	.attr = { .name = __stringify(field), .mode = 0444 },         \
  	.show = show_modinfo_##field,                                 \
  	.setup = setup_modinfo_##field,                               \
  	.test = modinfo_##field##_exists,                             \
  	.free = free_modinfo_##field,                                 \
  };
  
  MODINFO_ATTR(version);
  MODINFO_ATTR(srcversion);
  
  static char last_unloaded_module[MODULE_NAME_LEN+1];
  
  #ifdef CONFIG_MODULE_UNLOAD
  
  EXPORT_TRACEPOINT_SYMBOL(module_get);
  
  /* Init the unload section of the module. */
  static int module_unload_init(struct module *mod)
  {
  	mod->refptr = alloc_percpu(struct module_ref);
  	if (!mod->refptr)
  		return -ENOMEM;
  
  	INIT_LIST_HEAD(&mod->source_list);
  	INIT_LIST_HEAD(&mod->target_list);
  
  	/* Hold reference count during initialization. */
  	__this_cpu_write(mod->refptr->incs, 1);
  	/* Backwards compatibility macros put refcount during init. */
  	mod->waiter = current;
  
  	return 0;
  }
  
  /* Does a already use b? */
  static int already_uses(struct module *a, struct module *b)
  {
  	struct module_use *use;
  
  	list_for_each_entry(use, &b->source_list, source_list) {
  		if (use->source == a) {
  			DEBUGP("%s uses %s!\n", a->name, b->name);
  			return 1;
  		}
  	}
  	DEBUGP("%s does not use %s!\n", a->name, b->name);
  	return 0;
  }
  
  /*
   * Module a uses b
   *  - we add 'a' as a "source", 'b' as a "target" of module use
   *  - the module_use is added to the list of 'b' sources (so
   *    'b' can walk the list to see who sourced them), and of 'a'
   *    targets (so 'a' can see what modules it targets).
   */
  static int add_module_usage(struct module *a, struct module *b)
  {
  	struct module_use *use;
  
  	DEBUGP("Allocating new usage for %s.\n", a->name);
  	use = kmalloc(sizeof(*use), GFP_ATOMIC);
  	if (!use) {
  		printk(KERN_WARNING "%s: out of memory loading\n", a->name);
  		return -ENOMEM;
  	}
  
  	use->source = a;
  	use->target = b;
  	list_add(&use->source_list, &b->source_list);
  	list_add(&use->target_list, &a->target_list);
  	return 0;
  }
  
  /* Module a uses b: caller needs module_mutex() */
  int ref_module(struct module *a, struct module *b)
  {
  	int err;
  
  	if (b == NULL || already_uses(a, b))
  		return 0;
  
  	/* If module isn't available, we fail. */
  	err = strong_try_module_get(b);
  	if (err)
  		return err;
  
  	err = add_module_usage(a, b);
  	if (err) {
  		module_put(b);
  		return err;
  	}
  	return 0;
  }
  EXPORT_SYMBOL_GPL(ref_module);
  
  /* Clear the unload stuff of the module. */
  static void module_unload_free(struct module *mod)
  {
  	struct module_use *use, *tmp;
  
  	mutex_lock(&module_mutex);
  	list_for_each_entry_safe(use, tmp, &mod->target_list, target_list) {
  		struct module *i = use->target;
  		DEBUGP("%s unusing %s\n", mod->name, i->name);
  		module_put(i);
  		list_del(&use->source_list);
  		list_del(&use->target_list);
  		kfree(use);
  	}
  	mutex_unlock(&module_mutex);
  
  	free_percpu(mod->refptr);
  }
  
  #ifdef CONFIG_MODULE_FORCE_UNLOAD
  static inline int try_force_unload(unsigned int flags)
  {
  	int ret = (flags & O_TRUNC);
  	if (ret)
  		add_taint(TAINT_FORCED_RMMOD);
  	return ret;
  }
  #else
  static inline int try_force_unload(unsigned int flags)
  {
  	return 0;
  }
  #endif /* CONFIG_MODULE_FORCE_UNLOAD */
  
  struct stopref
  {
  	struct module *mod;
  	int flags;
  	int *forced;
  };
  
  /* Whole machine is stopped with interrupts off when this runs. */
  static int __try_stop_module(void *_sref)
  {
  	struct stopref *sref = _sref;
  
  	/* If it's not unused, quit unless we're forcing. */
  	if (module_refcount(sref->mod) != 0) {
  		if (!(*sref->forced = try_force_unload(sref->flags)))
  			return -EWOULDBLOCK;
  	}
  
  	/* Mark it as dying. */
  	sref->mod->state = MODULE_STATE_GOING;
  	return 0;
  }
  
  static int try_stop_module(struct module *mod, int flags, int *forced)
  {
  	if (flags & O_NONBLOCK) {
  		struct stopref sref = { mod, flags, forced };
  
  		return stop_machine(__try_stop_module, &sref, NULL);
  	} else {
  		/* We don't need to stop the machine for this. */
  		mod->state = MODULE_STATE_GOING;
  		synchronize_sched();
  		return 0;
  	}
  }
  
  unsigned int module_refcount(struct module *mod)
  {
  	unsigned int incs = 0, decs = 0;
  	int cpu;
  
  	for_each_possible_cpu(cpu)
  		decs += per_cpu_ptr(mod->refptr, cpu)->decs;
  	/*
  	 * ensure the incs are added up after the decs.
  	 * module_put ensures incs are visible before decs with smp_wmb.
  	 *
  	 * This 2-count scheme avoids the situation where the refcount
  	 * for CPU0 is read, then CPU0 increments the module refcount,
  	 * then CPU1 drops that refcount, then the refcount for CPU1 is
  	 * read. We would record a decrement but not its corresponding
  	 * increment so we would see a low count (disaster).
  	 *
  	 * Rare situation? But module_refcount can be preempted, and we
  	 * might be tallying up 4096+ CPUs. So it is not impossible.
  	 */
  	smp_rmb();
  	for_each_possible_cpu(cpu)
  		incs += per_cpu_ptr(mod->refptr, cpu)->incs;
  	return incs - decs;
  }
  EXPORT_SYMBOL(module_refcount);
  
  /* This exists whether we can unload or not */
  static void free_module(struct module *mod);
  
  static void wait_for_zero_refcount(struct module *mod)
  {
  	/* Since we might sleep for some time, release the mutex first */
  	mutex_unlock(&module_mutex);
  	for (;;) {
  		DEBUGP("Looking at refcount...\n");
  		set_current_state(TASK_UNINTERRUPTIBLE);
  		if (module_refcount(mod) == 0)
  			break;
  		schedule();
  	}
  	current->state = TASK_RUNNING;
  	mutex_lock(&module_mutex);
  }
  
  SYSCALL_DEFINE2(delete_module, const char __user *, name_user,
  		unsigned int, flags)
  {
  	struct module *mod;
  	char name[MODULE_NAME_LEN];
  	int ret, forced = 0;
  
  	if (!capable(CAP_SYS_MODULE) || modules_disabled)
  		return -EPERM;
  
  	if (strncpy_from_user(name, name_user, MODULE_NAME_LEN-1) < 0)
  		return -EFAULT;
  	name[MODULE_NAME_LEN-1] = '\0';
  
  	if (mutex_lock_interruptible(&module_mutex) != 0)
  		return -EINTR;
  
  	mod = find_module(name);
  	if (!mod) {
  		ret = -ENOENT;
  		goto out;
  	}
  
  	if (!list_empty(&mod->source_list)) {
  		/* Other modules depend on us: get rid of them first. */
  		ret = -EWOULDBLOCK;
  		goto out;
  	}
  
  	/* Doing init or already dying? */
  	if (mod->state != MODULE_STATE_LIVE) {
  		/* FIXME: if (force), slam module count and wake up
                     waiter --RR */
  		DEBUGP("%s already dying\n", mod->name);
  		ret = -EBUSY;
  		goto out;
  	}
  
  	/* If it has an init func, it must have an exit func to unload */
  	if (mod->init && !mod->exit) {
  		forced = try_force_unload(flags);
  		if (!forced) {
  			/* This module can't be removed */
  			ret = -EBUSY;
  			goto out;
  		}
  	}
  
  	/* Set this up before setting mod->state */
  	mod->waiter = current;
  
  	/* Stop the machine so refcounts can't move and disable module. */
  	ret = try_stop_module(mod, flags, &forced);
  	if (ret != 0)
  		goto out;
  
  	/* Never wait if forced. */
  	if (!forced && module_refcount(mod) != 0)
  		wait_for_zero_refcount(mod);
  
  	mutex_unlock(&module_mutex);
  	/* Final destruction now no one is using it. */
  	if (mod->exit != NULL)
  		mod->exit();
  	blocking_notifier_call_chain(&module_notify_list,
  				     MODULE_STATE_GOING, mod);
  	async_synchronize_full();
  
  	/* Store the name of the last unloaded module for diagnostic purposes */
  	strlcpy(last_unloaded_module, mod->name, sizeof(last_unloaded_module));
  
  	free_module(mod);
  	return 0;
  out:
  	mutex_unlock(&module_mutex);
  	return ret;
  }
  
  static inline void print_unload_info(struct seq_file *m, struct module *mod)
  {
  	struct module_use *use;
  	int printed_something = 0;
  
  	seq_printf(m, " %u ", module_refcount(mod));
  
  	/* Always include a trailing , so userspace can differentiate
             between this and the old multi-field proc format. */
  	list_for_each_entry(use, &mod->source_list, source_list) {
  		printed_something = 1;
  		seq_printf(m, "%s,", use->source->name);
  	}
  
  	if (mod->init != NULL && mod->exit == NULL) {
  		printed_something = 1;
  		seq_printf(m, "[permanent],");
  	}
  
  	if (!printed_something)
  		seq_printf(m, "-");
  }
  
  void __symbol_put(const char *symbol)
  {
  	struct module *owner;
  
  	preempt_disable();
  	if (!find_symbol(symbol, &owner, NULL, true, false))
  		BUG();
  	module_put(owner);
  	preempt_enable();
  }
  EXPORT_SYMBOL(__symbol_put);
  
  /* Note this assumes addr is a function, which it currently always is. */
  void symbol_put_addr(void *addr)
  {
  	struct module *modaddr;
  	unsigned long a = (unsigned long)dereference_function_descriptor(addr);
  
  	if (core_kernel_text(a))
  		return;
  
  	/* module_text_address is safe here: we're supposed to have reference
  	 * to module from symbol_get, so it can't go away. */
  	modaddr = __module_text_address(a);
  	BUG_ON(!modaddr);
  	module_put(modaddr);
  }
  EXPORT_SYMBOL_GPL(symbol_put_addr);
  
  static ssize_t show_refcnt(struct module_attribute *mattr,
  			   struct module *mod, char *buffer)
  {
  	return sprintf(buffer, "%u\n", module_refcount(mod));
  }
  
  static struct module_attribute refcnt = {
  	.attr = { .name = "refcnt", .mode = 0444 },
  	.show = show_refcnt,
  };
  
  void module_put(struct module *module)
  {
  	if (module) {
  		preempt_disable();
  		smp_wmb(); /* see comment in module_refcount */
  		__this_cpu_inc(module->refptr->decs);
  
  		trace_module_put(module, _RET_IP_);
  		/* Maybe they're waiting for us to drop reference? */
  		if (unlikely(!module_is_live(module)))
  			wake_up_process(module->waiter);
  		preempt_enable();
  	}
  }
  EXPORT_SYMBOL(module_put);
  
  #else /* !CONFIG_MODULE_UNLOAD */
  static inline void print_unload_info(struct seq_file *m, struct module *mod)
  {
  	/* We don't know the usage count, or what modules are using. */
  	seq_printf(m, " - -");
  }
  
  static inline void module_unload_free(struct module *mod)
  {
  }
  
  int ref_module(struct module *a, struct module *b)
  {
  	return strong_try_module_get(b);
  }
  EXPORT_SYMBOL_GPL(ref_module);
  
  static inline int module_unload_init(struct module *mod)
  {
  	return 0;
  }
  #endif /* CONFIG_MODULE_UNLOAD */
  
  static ssize_t show_initstate(struct module_attribute *mattr,
  			   struct module *mod, char *buffer)
  {
  	const char *state = "unknown";
  
  	switch (mod->state) {
  	case MODULE_STATE_LIVE:
  		state = "live";
  		break;
  	case MODULE_STATE_COMING:
  		state = "coming";
  		break;
  	case MODULE_STATE_GOING:
  		state = "going";
  		break;
  	}
  	return sprintf(buffer, "%s\n", state);
  }
  
  static struct module_attribute initstate = {
  	.attr = { .name = "initstate", .mode = 0444 },
  	.show = show_initstate,
  };
  
  static struct module_attribute *modinfo_attrs[] = {
  	&modinfo_version,
  	&modinfo_srcversion,
  	&initstate,
  #ifdef CONFIG_MODULE_UNLOAD
  	&refcnt,
  #endif
  	NULL,
  };
  
  static const char vermagic[] = VERMAGIC_STRING;
  
  static int try_to_force_load(struct module *mod, const char *reason)
  {
  #ifdef CONFIG_MODULE_FORCE_LOAD
  	if (!test_taint(TAINT_FORCED_MODULE))
  		printk(KERN_WARNING "%s: %s: kernel tainted.\n",
  		       mod->name, reason);
  	add_taint_module(mod, TAINT_FORCED_MODULE);
  	return 0;
  #else
  	return -ENOEXEC;
  #endif
  }
  
  #ifdef CONFIG_MODVERSIONS
  /* If the arch applies (non-zero) relocations to kernel kcrctab, unapply it. */
  static unsigned long maybe_relocated(unsigned long crc,
  				     const struct module *crc_owner)
  {
  #ifdef ARCH_RELOCATES_KCRCTAB
  	if (crc_owner == NULL)
  		return crc - (unsigned long)reloc_start;
  #endif
  	return crc;
  }
  
  static int check_version(Elf_Shdr *sechdrs,
  			 unsigned int versindex,
  			 const char *symname,
  			 struct module *mod, 
  			 const unsigned long *crc,
  			 const struct module *crc_owner)
  {
  	unsigned int i, num_versions;
  	struct modversion_info *versions;
  
  	/* Exporting module didn't supply crcs?  OK, we're already tainted. */
  	if (!crc)
  		return 1;
  
  	/* No versions at all?  modprobe --force does this. */
  	if (versindex == 0)
  		return try_to_force_load(mod, symname) == 0;
  
  	versions = (void *) sechdrs[versindex].sh_addr;
  	num_versions = sechdrs[versindex].sh_size
  		/ sizeof(struct modversion_info);
  
  	for (i = 0; i < num_versions; i++) {
  		if (strcmp(versions[i].name, symname) != 0)
  			continue;
  
  		if (versions[i].crc == maybe_relocated(*crc, crc_owner))
  			return 1;
  		DEBUGP("Found checksum %lX vs module %lX\n",
  		       maybe_relocated(*crc, crc_owner), versions[i].crc);
  		goto bad_version;
  	}
  
  	printk(KERN_WARNING "%s: no symbol version for %s\n",
  	       mod->name, symname);
  	return 0;
  
  bad_version:
  	printk("%s: disagrees about version of symbol %s\n",
  	       mod->name, symname);
  	return 0;
  }
  
  static inline int check_modstruct_version(Elf_Shdr *sechdrs,
  					  unsigned int versindex,
  					  struct module *mod)
  {
  	const unsigned long *crc;
  
  	/* Since this should be found in kernel (which can't be removed),
  	 * no locking is necessary. */
  	if (!find_symbol(MODULE_SYMBOL_PREFIX "module_layout", NULL,
  			 &crc, true, false))
  		BUG();
  	return check_version(sechdrs, versindex, "module_layout", mod, crc,
  			     NULL);
  }
  
  /* First part is kernel version, which we ignore if module has crcs. */
  static inline int same_magic(const char *amagic, const char *bmagic,
  			     bool has_crcs)
  {
  	if (has_crcs) {
  		amagic += strcspn(amagic, " ");
  		bmagic += strcspn(bmagic, " ");
  	}
  	return strcmp(amagic, bmagic) == 0;
  }
  #else
  static inline int check_version(Elf_Shdr *sechdrs,
  				unsigned int versindex,
  				const char *symname,
  				struct module *mod, 
  				const unsigned long *crc,
  				const struct module *crc_owner)
  {
  	return 1;
  }
  
  static inline int check_modstruct_version(Elf_Shdr *sechdrs,
  					  unsigned int versindex,
  					  struct module *mod)
  {
  	return 1;
  }
  
  static inline int same_magic(const char *amagic, const char *bmagic,
  			     bool has_crcs)
  {
  	return strcmp(amagic, bmagic) == 0;
  }
  #endif /* CONFIG_MODVERSIONS */
  
  /* Resolve a symbol for this module.  I.e. if we find one, record usage. */
  static const struct kernel_symbol *resolve_symbol(struct module *mod,
  						  const struct load_info *info,
  						  const char *name,
  						  char ownername[])
  {
  	struct module *owner;
  	const struct kernel_symbol *sym;
  	const unsigned long *crc;
  	int err;
  
  	mutex_lock(&module_mutex);
  	sym = find_symbol(name, &owner, &crc,
  			  !(mod->taints & (1 << TAINT_PROPRIETARY_MODULE)), true);
  	if (!sym)
  		goto unlock;
  
  	if (!check_version(info->sechdrs, info->index.vers, name, mod, crc,
  			   owner)) {
  		sym = ERR_PTR(-EINVAL);
  		goto getname;
  	}
  
  	err = ref_module(mod, owner);
  	if (err) {
  		sym = ERR_PTR(err);
  		goto getname;
  	}
  
  getname:
  	/* We must make copy under the lock if we failed to get ref. */
  	strncpy(ownername, module_name(owner), MODULE_NAME_LEN);
  unlock:
  	mutex_unlock(&module_mutex);
  	return sym;
  }
  
  static const struct kernel_symbol *
  resolve_symbol_wait(struct module *mod,
  		    const struct load_info *info,
  		    const char *name)
  {
  	const struct kernel_symbol *ksym;
  	char owner[MODULE_NAME_LEN];
  
  	if (wait_event_interruptible_timeout(module_wq,
  			!IS_ERR(ksym = resolve_symbol(mod, info, name, owner))
  			|| PTR_ERR(ksym) != -EBUSY,
  					     30 * HZ) <= 0) {
  		printk(KERN_WARNING "%s: gave up waiting for init of module %s.\n",
  		       mod->name, owner);
  	}
  	return ksym;
  }
  
  /*
   * /sys/module/foo/sections stuff
   * J. Corbet <corbet@lwn.net>
   */
  #ifdef CONFIG_SYSFS
  
  #ifdef CONFIG_KALLSYMS
  static inline bool sect_empty(const Elf_Shdr *sect)
  {
  	return !(sect->sh_flags & SHF_ALLOC) || sect->sh_size == 0;
  }
  
  struct module_sect_attr
  {
  	struct module_attribute mattr;
  	char *name;
  	unsigned long address;
  };
  
  struct module_sect_attrs
  {
  	struct attribute_group grp;
  	unsigned int nsections;
  	struct module_sect_attr attrs[0];
  };
  
  static ssize_t module_sect_show(struct module_attribute *mattr,
  				struct module *mod, char *buf)
  {
  	struct module_sect_attr *sattr =
  		container_of(mattr, struct module_sect_attr, mattr);
  	return sprintf(buf, "0x%pK\n", (void *)sattr->address);
  }
  
  static void free_sect_attrs(struct module_sect_attrs *sect_attrs)
  {
  	unsigned int section;
  
  	for (section = 0; section < sect_attrs->nsections; section++)
  		kfree(sect_attrs->attrs[section].name);
  	kfree(sect_attrs);
  }
  
  static void add_sect_attrs(struct module *mod, const struct load_info *info)
  {
  	unsigned int nloaded = 0, i, size[2];
  	struct module_sect_attrs *sect_attrs;
  	struct module_sect_attr *sattr;
  	struct attribute **gattr;
  
  	/* Count loaded sections and allocate structures */
  	for (i = 0; i < info->hdr->e_shnum; i++)
  		if (!sect_empty(&info->sechdrs[i]))
  			nloaded++;
  	size[0] = ALIGN(sizeof(*sect_attrs)
  			+ nloaded * sizeof(sect_attrs->attrs[0]),
  			sizeof(sect_attrs->grp.attrs[0]));
  	size[1] = (nloaded + 1) * sizeof(sect_attrs->grp.attrs[0]);
  	sect_attrs = kzalloc(size[0] + size[1], GFP_KERNEL);
  	if (sect_attrs == NULL)
  		return;
  
  	/* Setup section attributes. */
  	sect_attrs->grp.name = "sections";
  	sect_attrs->grp.attrs = (void *)sect_attrs + size[0];
  
  	sect_attrs->nsections = 0;
  	sattr = &sect_attrs->attrs[0];
  	gattr = &sect_attrs->grp.attrs[0];
  	for (i = 0; i < info->hdr->e_shnum; i++) {
  		Elf_Shdr *sec = &info->sechdrs[i];
  		if (sect_empty(sec))
  			continue;
  		sattr->address = sec->sh_addr;
  		sattr->name = kstrdup(info->secstrings + sec->sh_name,
  					GFP_KERNEL);
  		if (sattr->name == NULL)
  			goto out;
  		sect_attrs->nsections++;
  		sysfs_attr_init(&sattr->mattr.attr);
  		sattr->mattr.show = module_sect_show;
  		sattr->mattr.store = NULL;
  		sattr->mattr.attr.name = sattr->name;
  		sattr->mattr.attr.mode = S_IRUGO;
  		*(gattr++) = &(sattr++)->mattr.attr;
  	}
  	*gattr = NULL;
  
  	if (sysfs_create_group(&mod->mkobj.kobj, &sect_attrs->grp))
  		goto out;
  
  	mod->sect_attrs = sect_attrs;
  	return;
    out:
  	free_sect_attrs(sect_attrs);
  }
  
  static void remove_sect_attrs(struct module *mod)
  {
  	if (mod->sect_attrs) {
  		sysfs_remove_group(&mod->mkobj.kobj,
  				   &mod->sect_attrs->grp);
  		/* We are positive that no one is using any sect attrs
  		 * at this point.  Deallocate immediately. */
  		free_sect_attrs(mod->sect_attrs);
  		mod->sect_attrs = NULL;
  	}
  }
  
  /*
   * /sys/module/foo/notes/.section.name gives contents of SHT_NOTE sections.
   */
  
  struct module_notes_attrs {
  	struct kobject *dir;
  	unsigned int notes;
  	struct bin_attribute attrs[0];
  };
  
  static ssize_t module_notes_read(struct file *filp, struct kobject *kobj,
  				 struct bin_attribute *bin_attr,
  				 char *buf, loff_t pos, size_t count)
  {
  	/*
  	 * The caller checked the pos and count against our size.
  	 */
  	memcpy(buf, bin_attr->private + pos, count);
  	return count;
  }
  
  static void free_notes_attrs(struct module_notes_attrs *notes_attrs,
  			     unsigned int i)
  {
  	if (notes_attrs->dir) {
  		while (i-- > 0)
  			sysfs_remove_bin_file(notes_attrs->dir,
  					      &notes_attrs->attrs[i]);
  		kobject_put(notes_attrs->dir);
  	}
  	kfree(notes_attrs);
  }
  
  static void add_notes_attrs(struct module *mod, const struct load_info *info)
  {
  	unsigned int notes, loaded, i;
  	struct module_notes_attrs *notes_attrs;
  	struct bin_attribute *nattr;
  
  	/* failed to create section attributes, so can't create notes */
  	if (!mod->sect_attrs)
  		return;
  
  	/* Count notes sections and allocate structures.  */
  	notes = 0;
  	for (i = 0; i < info->hdr->e_shnum; i++)
  		if (!sect_empty(&info->sechdrs[i]) &&
  		    (info->sechdrs[i].sh_type == SHT_NOTE))
  			++notes;
  
  	if (notes == 0)
  		return;
  
  	notes_attrs = kzalloc(sizeof(*notes_attrs)
  			      + notes * sizeof(notes_attrs->attrs[0]),
  			      GFP_KERNEL);
  	if (notes_attrs == NULL)
  		return;
  
  	notes_attrs->notes = notes;
  	nattr = &notes_attrs->attrs[0];
  	for (loaded = i = 0; i < info->hdr->e_shnum; ++i) {
  		if (sect_empty(&info->sechdrs[i]))
  			continue;
  		if (info->sechdrs[i].sh_type == SHT_NOTE) {
  			sysfs_bin_attr_init(nattr);
  			nattr->attr.name = mod->sect_attrs->attrs[loaded].name;
  			nattr->attr.mode = S_IRUGO;
  			nattr->size = info->sechdrs[i].sh_size;
  			nattr->private = (void *) info->sechdrs[i].sh_addr;
  			nattr->read = module_notes_read;
  			++nattr;
  		}
  		++loaded;
  	}
  
  	notes_attrs->dir = kobject_create_and_add("notes", &mod->mkobj.kobj);
  	if (!notes_attrs->dir)
  		goto out;
  
  	for (i = 0; i < notes; ++i)
  		if (sysfs_create_bin_file(notes_attrs->dir,
  					  &notes_attrs->attrs[i]))
  			goto out;
  
  	mod->notes_attrs = notes_attrs;
  	return;
  
    out:
  	free_notes_attrs(notes_attrs, i);
  }
  
  static void remove_notes_attrs(struct module *mod)
  {
  	if (mod->notes_attrs)
  		free_notes_attrs(mod->notes_attrs, mod->notes_attrs->notes);
  }
  
  #else
  
  static inline void add_sect_attrs(struct module *mod,
  				  const struct load_info *info)
  {
  }
  
  static inline void remove_sect_attrs(struct module *mod)
  {
  }
  
  static inline void add_notes_attrs(struct module *mod,
  				   const struct load_info *info)
  {
  }
  
  static inline void remove_notes_attrs(struct module *mod)
  {
  }
  #endif /* CONFIG_KALLSYMS */
  
  static void add_usage_links(struct module *mod)
  {
  #ifdef CONFIG_MODULE_UNLOAD
  	struct module_use *use;
  	int nowarn;
  
  	mutex_lock(&module_mutex);
  	list_for_each_entry(use, &mod->target_list, target_list) {
  		nowarn = sysfs_create_link(use->target->holders_dir,
  					   &mod->mkobj.kobj, mod->name);
  	}
  	mutex_unlock(&module_mutex);
  #endif
  }
  
  static void del_usage_links(struct module *mod)
  {
  #ifdef CONFIG_MODULE_UNLOAD
  	struct module_use *use;
  
  	mutex_lock(&module_mutex);
  	list_for_each_entry(use, &mod->target_list, target_list)
  		sysfs_remove_link(use->target->holders_dir, mod->name);
  	mutex_unlock(&module_mutex);
  #endif
  }
  
  static int module_add_modinfo_attrs(struct module *mod)
  {
  	struct module_attribute *attr;
  	struct module_attribute *temp_attr;
  	int error = 0;
  	int i;
  
  	mod->modinfo_attrs = kzalloc((sizeof(struct module_attribute) *
  					(ARRAY_SIZE(modinfo_attrs) + 1)),
  					GFP_KERNEL);
  	if (!mod->modinfo_attrs)
  		return -ENOMEM;
  
  	temp_attr = mod->modinfo_attrs;
  	for (i = 0; (attr = modinfo_attrs[i]) && !error; i++) {
  		if (!attr->test ||
  		    (attr->test && attr->test(mod))) {
  			memcpy(temp_attr, attr, sizeof(*temp_attr));
  			sysfs_attr_init(&temp_attr->attr);
  			error = sysfs_create_file(&mod->mkobj.kobj,&temp_attr->attr);
  			++temp_attr;
  		}
  	}
  	return error;
  }
  
  static void module_remove_modinfo_attrs(struct module *mod)
  {
  	struct module_attribute *attr;
  	int i;
  
  	for (i = 0; (attr = &mod->modinfo_attrs[i]); i++) {
  		/* pick a field to test for end of list */
  		if (!attr->attr.name)
  			break;
  		sysfs_remove_file(&mod->mkobj.kobj,&attr->attr);
  		if (attr->free)
  			attr->free(mod);
  	}
  	kfree(mod->modinfo_attrs);
  }
  
  static int mod_sysfs_init(struct module *mod)
  {
  	int err;
  	struct kobject *kobj;
  
  	if (!module_sysfs_initialized) {
  		printk(KERN_ERR "%s: module sysfs not initialized\n",
  		       mod->name);
  		err = -EINVAL;
  		goto out;
  	}
  
  	kobj = kset_find_obj(module_kset, mod->name);
  	if (kobj) {
  		printk(KERN_ERR "%s: module is already loaded\n", mod->name);
  		kobject_put(kobj);
  		err = -EINVAL;
  		goto out;
  	}
  
  	mod->mkobj.mod = mod;
  
  	memset(&mod->mkobj.kobj, 0, sizeof(mod->mkobj.kobj));
  	mod->mkobj.kobj.kset = module_kset;
  	err = kobject_init_and_add(&mod->mkobj.kobj, &module_ktype, NULL,
  				   "%s", mod->name);
  	if (err)
  		kobject_put(&mod->mkobj.kobj);
  
  	/* delay uevent until full sysfs population */
  out:
  	return err;
  }
  
  static int mod_sysfs_setup(struct module *mod,
  			   const struct load_info *info,
  			   struct kernel_param *kparam,
  			   unsigned int num_params)
  {
  	int err;
  
  	err = mod_sysfs_init(mod);
  	if (err)
  		goto out;
  
  	mod->holders_dir = kobject_create_and_add("holders", &mod->mkobj.kobj);
  	if (!mod->holders_dir) {
  		err = -ENOMEM;
  		goto out_unreg;
  	}
  
  	err = module_param_sysfs_setup(mod, kparam, num_params);
  	if (err)
  		goto out_unreg_holders;
  
  	err = module_add_modinfo_attrs(mod);
  	if (err)
  		goto out_unreg_param;
  
  	add_usage_links(mod);
  	add_sect_attrs(mod, info);
  	add_notes_attrs(mod, info);
  
  	kobject_uevent(&mod->mkobj.kobj, KOBJ_ADD);
  	return 0;
  
  out_unreg_param:
  	module_param_sysfs_remove(mod);
  out_unreg_holders:
  	kobject_put(mod->holders_dir);
  out_unreg:
  	kobject_put(&mod->mkobj.kobj);
  out:
  	return err;
  }
  
  static void mod_sysfs_fini(struct module *mod)
  {
  	remove_notes_attrs(mod);
  	remove_sect_attrs(mod);
  	kobject_put(&mod->mkobj.kobj);
  }
  
  #else /* !CONFIG_SYSFS */
  
  static int mod_sysfs_setup(struct module *mod,
  			   const struct load_info *info,
  			   struct kernel_param *kparam,
  			   unsigned int num_params)
  {
  	return 0;
  }
  
  static void mod_sysfs_fini(struct module *mod)
  {
  }
  
  static void module_remove_modinfo_attrs(struct module *mod)
  {
  }
  
  static void del_usage_links(struct module *mod)
  {
  }
  
  #endif /* CONFIG_SYSFS */
  
  static void mod_sysfs_teardown(struct module *mod)
  {
  	del_usage_links(mod);
  	module_remove_modinfo_attrs(mod);
  	module_param_sysfs_remove(mod);
  	kobject_put(mod->mkobj.drivers_dir);
  	kobject_put(mod->holders_dir);
  	mod_sysfs_fini(mod);
  }
  
  /*
   * unlink the module with the whole machine is stopped with interrupts off
   * - this defends against kallsyms not taking locks
   */
  static int __unlink_module(void *_mod)
  {
  	struct module *mod = _mod;
  	list_del(&mod->list);
  	module_bug_cleanup(mod);
  	return 0;
  }
  
  #ifdef CONFIG_DEBUG_SET_MODULE_RONX
  /*
   * LKM RO/NX protection: protect module's text/ro-data
   * from modification and any data from execution.
   */
  void set_page_attributes(void *start, void *end, int (*set)(unsigned long start, int num_pages))
  {
  	unsigned long begin_pfn = PFN_DOWN((unsigned long)start);
  	unsigned long end_pfn = PFN_DOWN((unsigned long)end);
  
  	if (end_pfn > begin_pfn)
  		set(begin_pfn << PAGE_SHIFT, end_pfn - begin_pfn);
  }
  
  static void set_section_ro_nx(void *base,
  			unsigned long text_size,
  			unsigned long ro_size,
  			unsigned long total_size)
  {
  	/* begin and end PFNs of the current subsection */
  	unsigned long begin_pfn;
  	unsigned long end_pfn;
  
  	/*
  	 * Set RO for module text and RO-data:
  	 * - Always protect first page.
  	 * - Do not protect last partial page.
  	 */
  	if (ro_size > 0)
  		set_page_attributes(base, base + ro_size, set_memory_ro);
  
  	/*
  	 * Set NX permissions for module data:
  	 * - Do not protect first partial page.
  	 * - Always protect last page.
  	 */
  	if (total_size > text_size) {
  		begin_pfn = PFN_UP((unsigned long)base + text_size);
  		end_pfn = PFN_UP((unsigned long)base + total_size);
  		if (end_pfn > begin_pfn)
  			set_memory_nx(begin_pfn << PAGE_SHIFT, end_pfn - begin_pfn);
  	}
  }
  
  static void unset_module_core_ro_nx(struct module *mod)
  {
  	set_page_attributes(mod->module_core + mod->core_text_size,
  		mod->module_core + mod->core_size,
  		set_memory_x);
  	set_page_attributes(mod->module_core,
  		mod->module_core + mod->core_ro_size,
  		set_memory_rw);
  }
  
  static void unset_module_init_ro_nx(struct module *mod)
  {
  	set_page_attributes(mod->module_init + mod->init_text_size,
  		mod->module_init + mod->init_size,
  		set_memory_x);
  	set_page_attributes(mod->module_init,
  		mod->module_init + mod->init_ro_size,
  		set_memory_rw);
  }
  
  /* Iterate through all modules and set each module's text as RW */
  void set_all_modules_text_rw(void)
  {
  	struct module *mod;
  
  	mutex_lock(&module_mutex);
  	list_for_each_entry_rcu(mod, &modules, list) {
  		if ((mod->module_core) && (mod->core_text_size)) {
  			set_page_attributes(mod->module_core,
  						mod->module_core + mod->core_text_size,
  						set_memory_rw);
  		}
  		if ((mod->module_init) && (mod->init_text_size)) {
  			set_page_attributes(mod->module_init,
  						mod->module_init + mod->init_text_size,
  						set_memory_rw);
  		}
  	}
  	mutex_unlock(&module_mutex);
  }
  
  /* Iterate through all modules and set each module's text as RO */
  void set_all_modules_text_ro(void)
  {
  	struct module *mod;
  
  	mutex_lock(&module_mutex);
  	list_for_each_entry_rcu(mod, &modules, list) {
  		if ((mod->module_core) && (mod->core_text_size)) {
  			set_page_attributes(mod->module_core,
  						mod->module_core + mod->core_text_size,
  						set_memory_ro);
  		}
  		if ((mod->module_init) && (mod->init_text_size)) {
  			set_page_attributes(mod->module_init,
  						mod->module_init + mod->init_text_size,
  						set_memory_ro);
  		}
  	}
  	mutex_unlock(&module_mutex);
  }
  #else
  static inline void set_section_ro_nx(void *base, unsigned long text_size, unsigned long ro_size, unsigned long total_size) { }
  static void unset_module_core_ro_nx(struct module *mod) { }
  static void unset_module_init_ro_nx(struct module *mod) { }
  #endif
  
  /* Free a module, remove from lists, etc. */
  static void free_module(struct module *mod)
  {
  	trace_module_free(mod);
  
  	/* Delete from various lists */
  	mutex_lock(&module_mutex);
  	stop_machine(__unlink_module, mod, NULL);
  	mutex_unlock(&module_mutex);
  	mod_sysfs_teardown(mod);
  
  	/* Remove dynamic debug info */
  	ddebug_remove_module(mod->name);
  
  	/* Arch-specific cleanup. */
  	module_arch_cleanup(mod);
  
  	/* Module unload stuff */
  	module_unload_free(mod);
  
  	/* Free any allocated parameters. */
  	destroy_params(mod->kp, mod->num_kp);
  
  	/* This may be NULL, but that's OK */
  	unset_module_init_ro_nx(mod);
  	module_free(mod, mod->module_init);
  	kfree(mod->args);
  	percpu_modfree(mod);
  
  	/* Free lock-classes: */
  	lockdep_free_key_range(mod->module_core, mod->core_size);
  
  	/* Finally, free the core (containing the module structure) */
  	unset_module_core_ro_nx(mod);
  	module_free(mod, mod->module_core);
  
  #ifdef CONFIG_MPU
  	update_protections(current->mm);
  #endif
  }
  
  void *__symbol_get(const char *symbol)
  {
  	struct module *owner;
  	const struct kernel_symbol *sym;
  
  	preempt_disable();
  	sym = find_symbol(symbol, &owner, NULL, true, true);
  	if (sym && strong_try_module_get(owner))
  		sym = NULL;
  	preempt_enable();
  
  	return sym ? (void *)sym->value : NULL;
  }
  EXPORT_SYMBOL_GPL(__symbol_get);
  
  /*
   * Ensure that an exported symbol [global namespace] does not already exist
   * in the kernel or in some other module's exported symbol table.
   *
   * You must hold the module_mutex.
   */
  static int verify_export_symbols(struct module *mod)
  {
  	unsigned int i;
  	struct module *owner;
  	const struct kernel_symbol *s;
  	struct {
  		const struct kernel_symbol *sym;
  		unsigned int num;
  	} arr[] = {
  		{ mod->syms, mod->num_syms },
  		{ mod->gpl_syms, mod->num_gpl_syms },
  		{ mod->gpl_future_syms, mod->num_gpl_future_syms },
  #ifdef CONFIG_UNUSED_SYMBOLS
  		{ mod->unused_syms, mod->num_unused_syms },
  		{ mod->unused_gpl_syms, mod->num_unused_gpl_syms },
  #endif
  	};
  
  	for (i = 0; i < ARRAY_SIZE(arr); i++) {
  		for (s = arr[i].sym; s < arr[i].sym + arr[i].num; s++) {
  			if (find_symbol(s->name, &owner, NULL, true, false)) {
  				printk(KERN_ERR
  				       "%s: exports duplicate symbol %s"
  				       " (owned by %s)\n",
  				       mod->name, s->name, module_name(owner));
  				return -ENOEXEC;
  			}
  		}
  	}
  	return 0;
  }
  
  /* Change all symbols so that st_value encodes the pointer directly. */
  static int simplify_symbols(struct module *mod, const struct load_info *info)
  {
  	Elf_Shdr *symsec = &info->sechdrs[info->index.sym];
  	Elf_Sym *sym = (void *)symsec->sh_addr;
  	unsigned long secbase;
  	unsigned int i;
  	int ret = 0;
  	const struct kernel_symbol *ksym;
  
  	for (i = 1; i < symsec->sh_size / sizeof(Elf_Sym); i++) {
  		const char *name = info->strtab + sym[i].st_name;
  
  		switch (sym[i].st_shndx) {
  		case SHN_COMMON:
  			/* We compiled with -fno-common.  These are not
  			   supposed to happen.  */
  			DEBUGP("Common symbol: %s\n", name);
  			printk("%s: please compile with -fno-common\n",
  			       mod->name);
  			ret = -ENOEXEC;
  			break;
  
  		case SHN_ABS:
  			/* Don't need to do anything */
  			DEBUGP("Absolute symbol: 0x%08lx\n",
  			       (long)sym[i].st_value);
  			break;
  
  		case SHN_UNDEF:
  			ksym = resolve_symbol_wait(mod, info, name);
  			/* Ok if resolved.  */
  			if (ksym && !IS_ERR(ksym)) {
  				sym[i].st_value = ksym->value;
  				break;
  			}
  
  			/* Ok if weak.  */
  			if (!ksym && ELF_ST_BIND(sym[i].st_info) == STB_WEAK)
  				break;
  
  			printk(KERN_WARNING "%s: Unknown symbol %s (err %li)\n",
  			       mod->name, name, PTR_ERR(ksym));
  			ret = PTR_ERR(ksym) ?: -ENOENT;
  			break;
  
  		default:
  			/* Divert to percpu allocation if a percpu var. */
  			if (sym[i].st_shndx == info->index.pcpu)
  				secbase = (unsigned long)mod_percpu(mod);
  			else
  				secbase = info->sechdrs[sym[i].st_shndx].sh_addr;
  			sym[i].st_value += secbase;
  			break;
  		}
  	}
  
  	return ret;
  }
  
  static int apply_relocations(struct module *mod, const struct load_info *info)
  {
  	unsigned int i;
  	int err = 0;
  
  	/* Now do relocations. */
  	for (i = 1; i < info->hdr->e_shnum; i++) {
  		unsigned int infosec = info->sechdrs[i].sh_info;
  
  		/* Not a valid relocation section? */
  		if (infosec >= info->hdr->e_shnum)
  			continue;
  
  		/* Don't bother with non-allocated sections */
  		if (!(info->sechdrs[infosec].sh_flags & SHF_ALLOC))
  			continue;
  
  		if (info->sechdrs[i].sh_type == SHT_REL)
  			err = apply_relocate(info->sechdrs, info->strtab,
  					     info->index.sym, i, mod);
  		else if (info->sechdrs[i].sh_type == SHT_RELA)
  			err = apply_relocate_add(info->sechdrs, info->strtab,
  						 info->index.sym, i, mod);
  		if (err < 0)
  			break;
  	}
  	return err;
  }
  
  /* Additional bytes needed by arch in front of individual sections */
  unsigned int __weak arch_mod_section_prepend(struct module *mod,
  					     unsigned int section)
  {
  	/* default implementation just returns zero */
  	return 0;
  }
  
  /* Update size with this section: return offset. */
  static long get_offset(struct module *mod, unsigned int *size,
  		       Elf_Shdr *sechdr, unsigned int section)
  {
  	long ret;
  
  	*size += arch_mod_section_prepend(mod, section);
  	ret = ALIGN(*size, sechdr->sh_addralign ?: 1);
  	*size = ret + sechdr->sh_size;
  	return ret;
  }
  
  /* Lay out the SHF_ALLOC sections in a way not dissimilar to how ld
     might -- code, read-only data, read-write data, small data.  Tally
     sizes, and place the offsets into sh_entsize fields: high bit means it
     belongs in init. */
  static void layout_sections(struct module *mod, struct load_info *info)
  {
  	static unsigned long const masks[][2] = {
  		/* NOTE: all executable code must be the first section
  		 * in this array; otherwise modify the text_size
  		 * finder in the two loops below */
  		{ SHF_EXECINSTR | SHF_ALLOC, ARCH_SHF_SMALL },
  		{ SHF_ALLOC, SHF_WRITE | ARCH_SHF_SMALL },
  		{ SHF_WRITE | SHF_ALLOC, ARCH_SHF_SMALL },
  		{ ARCH_SHF_SMALL | SHF_ALLOC, 0 }
  	};
  	unsigned int m, i;
  
  	for (i = 0; i < info->hdr->e_shnum; i++)
  		info->sechdrs[i].sh_entsize = ~0UL;
  
  	DEBUGP("Core section allocation order:\n");
  	for (m = 0; m < ARRAY_SIZE(masks); ++m) {
  		for (i = 0; i < info->hdr->e_shnum; ++i) {
  			Elf_Shdr *s = &info->sechdrs[i];
  			const char *sname = info->secstrings + s->sh_name;
  
  			if ((s->sh_flags & masks[m][0]) != masks[m][0]
  			    || (s->sh_flags & masks[m][1])
  			    || s->sh_entsize != ~0UL
  			    || strstarts(sname, ".init"))
  				continue;
  			s->sh_entsize = get_offset(mod, &mod->core_size, s, i);
  			DEBUGP("\t%s\n", name);
  		}
  		switch (m) {
  		case 0: /* executable */
  			mod->core_size = debug_align(mod->core_size);
  			mod->core_text_size = mod->core_size;
  			break;
  		case 1: /* RO: text and ro-data */
  			mod->core_size = debug_align(mod->core_size);
  			mod->core_ro_size = mod->core_size;
  			break;
  		case 3: /* whole core */
  			mod->core_size = debug_align(mod->core_size);
  			break;
  		}
  	}
  
  	DEBUGP("Init section allocation order:\n");
  	for (m = 0; m < ARRAY_SIZE(masks); ++m) {
  		for (i = 0; i < info->hdr->e_shnum; ++i) {
  			Elf_Shdr *s = &info->sechdrs[i];
  			const char *sname = info->secstrings + s->sh_name;
  
  			if ((s->sh_flags & masks[m][0]) != masks[m][0]
  			    || (s->sh_flags & masks[m][1])
  			    || s->sh_entsize != ~0UL
  			    || !strstarts(sname, ".init"))
  				continue;
  			s->sh_entsize = (get_offset(mod, &mod->init_size, s, i)
  					 | INIT_OFFSET_MASK);
  			DEBUGP("\t%s\n", sname);
  		}
  		switch (m) {
  		case 0: /* executable */
  			mod->init_size = debug_align(mod->init_size);
  			mod->init_text_size = mod->init_size;
  			break;
  		case 1: /* RO: text and ro-data */
  			mod->init_size = debug_align(mod->init_size);
  			mod->init_ro_size = mod->init_size;
  			break;
  		case 3: /* whole init */
  			mod->init_size = debug_align(mod->init_size);
  			break;
  		}
  	}
  }
  
  static void set_license(struct module *mod, const char *license)
  {
  	if (!license)
  		license = "unspecified";
  
  	if (!license_is_gpl_compatible(license)) {
  		if (!test_taint(TAINT_PROPRIETARY_MODULE))
  			printk(KERN_WARNING "%s: module license '%s' taints "
  				"kernel.\n", mod->name, license);
  		add_taint_module(mod, TAINT_PROPRIETARY_MODULE);
  	}
  }
  
  /* Parse tag=value strings from .modinfo section */
  static char *next_string(char *string, unsigned long *secsize)
  {
  	/* Skip non-zero chars */
  	while (string[0]) {
  		string++;
  		if ((*secsize)-- <= 1)
  			return NULL;
  	}
  
  	/* Skip any zero padding. */
  	while (!string[0]) {
  		string++;
  		if ((*secsize)-- <= 1)
  			return NULL;
  	}
  	return string;
  }
  
  static char *get_modinfo(struct load_info *info, const char *tag)
  {
  	char *p;
  	unsigned int taglen = strlen(tag);
  	Elf_Shdr *infosec = &info->sechdrs[info->index.info];
  	unsigned long size = infosec->sh_size;
  
  	for (p = (char *)infosec->sh_addr; p; p = next_string(p, &size)) {
  		if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=')
  			return p + taglen + 1;
  	}
  	return NULL;
  }
  
  static void setup_modinfo(struct module *mod, struct load_info *info)
  {
  	struct module_attribute *attr;
  	int i;
  
  	for (i = 0; (attr = modinfo_attrs[i]); i++) {
  		if (attr->setup)
  			attr->setup(mod, get_modinfo(info, attr->attr.name));
  	}
  }
  
  static void free_modinfo(struct module *mod)
  {
  	struct module_attribute *attr;
  	int i;
  
  	for (i = 0; (attr = modinfo_attrs[i]); i++) {
  		if (attr->free)
  			attr->free(mod);
  	}
  }
  
  #ifdef CONFIG_KALLSYMS
  
  /* lookup symbol in given range of kernel_symbols */
  static const struct kernel_symbol *lookup_symbol(const char *name,
  	const struct kernel_symbol *start,
  	const struct kernel_symbol *stop)
  {
  	return bsearch(name, start, stop - start,
  			sizeof(struct kernel_symbol), cmp_name);
  }
  
  static int is_exported(const char *name, unsigned long value,
  		       const struct module *mod)
  {
  	const struct kernel_symbol *ks;
  	if (!mod)
  		ks = lookup_symbol(name, __start___ksymtab, __stop___ksymtab);
  	else
  		ks = lookup_symbol(name, mod->syms, mod->syms + mod->num_syms);
  	return ks != NULL && ks->value == value;
  }
  
  /* As per nm */
  static char elf_type(const Elf_Sym *sym, const struct load_info *info)
  {
  	const Elf_Shdr *sechdrs = info->sechdrs;
  
  	if (ELF_ST_BIND(sym->st_info) == STB_WEAK) {
  		if (ELF_ST_TYPE(sym->st_info) == STT_OBJECT)
  			return 'v';
  		else
  			return 'w';
  	}
  	if (sym->st_shndx == SHN_UNDEF)
  		return 'U';
  	if (sym->st_shndx == SHN_ABS)
  		return 'a';
  	if (sym->st_shndx >= SHN_LORESERVE)
  		return '?';
  	if (sechdrs[sym->st_shndx].sh_flags & SHF_EXECINSTR)
  		return 't';
  	if (sechdrs[sym->st_shndx].sh_flags & SHF_ALLOC
  	    && sechdrs[sym->st_shndx].sh_type != SHT_NOBITS) {
  		if (!(sechdrs[sym->st_shndx].sh_flags & SHF_WRITE))
  			return 'r';
  		else if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
  			return 'g';
  		else
  			return 'd';
  	}
  	if (sechdrs[sym->st_shndx].sh_type == SHT_NOBITS) {
  		if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
  			return 's';
  		else
  			return 'b';
  	}
  	if (strstarts(info->secstrings + sechdrs[sym->st_shndx].sh_name,
  		      ".debug")) {
  		return 'n';
  	}
  	return '?';
  }
  
  static void add_kallsyms(struct module *mod, const struct load_info *info)
  {
  	unsigned int i;
  	Elf_Shdr *symsec = &info->sechdrs[info->index.sym];
  
  	mod->symtab = (void *)symsec->sh_addr;
  	mod->num_symtab = symsec->sh_size / sizeof(Elf_Sym);
  	/* Make sure we get permanent strtab: don't use info->strtab. */
  	mod->strtab = (void *)info->sechdrs[info->index.str].sh_addr;
  
  	/* Set types up while we still have access to sections. */
  	for (i = 0; i < mod->num_symtab; i++)
  		mod->symtab[i].st_info = elf_type(&mod->symtab[i], info);
  }
  #else
  static void add_kallsyms(struct module *mod, const struct load_info *info)
  {
  }
  #endif /* CONFIG_KALLSYMS */
  
  static void dynamic_debug_setup(struct _ddebug *debug, unsigned int num)
  {
  	if (!debug)
  		return;
  #ifdef CONFIG_DYNAMIC_DEBUG
  	if (ddebug_add_module(debug, num, debug->modname))
  		printk(KERN_ERR "dynamic debug error adding module: %s\n",
  					debug->modname);
  #endif
  }
  
  static void dynamic_debug_remove(struct _ddebug *debug)
  {
  	if (debug)
  		ddebug_remove_module(debug->modname);
  }
  
  static void *module_alloc_update_bounds(unsigned long size)
  {
  	void *ret = module_alloc(size);
  
  	if (ret) {
  		mutex_lock(&module_mutex);
  		/* Update module bounds. */
  		if ((unsigned long)ret < module_addr_min)
  			module_addr_min = (unsigned long)ret;
  		if ((unsigned long)ret + size > module_addr_max)
  			module_addr_max = (unsigned long)ret + size;
  		mutex_unlock(&module_mutex);
  	}
  	return ret;
  }
  
  #ifdef CONFIG_DEBUG_KMEMLEAK
  static void kmemleak_load_module(const struct module *mod,
  				 const struct load_info *info)
  {
  	unsigned int i;
  
  	/* only scan the sections containing data */
  	kmemleak_scan_area(mod, sizeof(struct module), GFP_KERNEL);
  
  	for (i = 1; i < info->hdr->e_shnum; i++) {
  		const char *name = info->secstrings + info->sechdrs[i].sh_name;
  		if (!(info->sechdrs[i].sh_flags & SHF_ALLOC))
  			continue;
  		if (!strstarts(name, ".data") && !strstarts(name, ".bss"))
  			continue;
  
  		kmemleak_scan_area((void *)info->sechdrs[i].sh_addr,
  				   info->sechdrs[i].sh_size, GFP_KERNEL);
  	}
  }
  #else
  static inline void kmemleak_load_module(const struct module *mod,
  					const struct load_info *info)
  {
  }
  #endif
  
  /* Sets info->hdr and info->len. */
  static int copy_and_check(struct load_info *info,
  			  const void __user *umod, unsigned long len,
  			  const char __user *uargs)
  {
  	int err;
  	Elf_Ehdr *hdr;
  
  	if (len < sizeof(*hdr))
  		return -ENOEXEC;
  
  	/* Suck in entire file: we'll want most of it. */
  	/* vmalloc barfs on "unusual" numbers.  Check here */
  	if (len > 64 * 1024 * 1024 || (hdr = vmalloc(len)) == NULL)
  		return -ENOMEM;
  
  	if (copy_from_user(hdr, umod, len) != 0) {
  		err = -EFAULT;
  		goto free_hdr;
  	}
  
  	/* Sanity checks against insmoding binaries or wrong arch,
  	   weird elf version */
  	if (memcmp(hdr->e_ident, ELFMAG, SELFMAG) != 0
  	    || hdr->e_type != ET_REL
  	    || !elf_check_arch(hdr)
  	    || hdr->e_shentsize != sizeof(Elf_Shdr)) {
  		err = -ENOEXEC;
  		goto free_hdr;
  	}
  
  	if (len < hdr->e_shoff + hdr->e_shnum * sizeof(Elf_Shdr)) {
  		err = -ENOEXEC;
  		goto free_hdr;
  	}
  
  	info->hdr = hdr;
  	info->len = len;
  	return 0;
  
  free_hdr:
  	vfree(hdr);
  	return err;
  }
  
  static void free_copy(struct load_info *info)
  {
  	vfree(info->hdr);
  }
  
  static int rewrite_section_headers(struct load_info *info)
  {
  	unsigned int i;
  
  	/* This should always be true, but let's be sure. */
  	info->sechdrs[0].sh_addr = 0;
  
  	for (i = 1; i < info->hdr->e_shnum; i++) {
  		Elf_Shdr *shdr = &info->sechdrs[i];
  		if (shdr->sh_type != SHT_NOBITS
  		    && info->len < shdr->sh_offset + shdr->sh_size) {
  			printk(KERN_ERR "Module len %lu truncated\n",
  			       info->len);
  			return -ENOEXEC;
  		}
  
  		/* Mark all sections sh_addr with their address in the
  		   temporary image. */
  		shdr->sh_addr = (size_t)info->hdr + shdr->sh_offset;
  
  #ifndef CONFIG_MODULE_UNLOAD
  		/* Don't load .exit sections */
  		if (strstarts(info->secstrings+shdr->sh_name, ".exit"))
  			shdr->sh_flags &= ~(unsigned long)SHF_ALLOC;
  #endif
  	}
  
  	/* Track but don't keep modinfo and version sections. */
  	info->index.vers = find_sec(info, "__versions");
  	info->index.info = find_sec(info, ".modinfo");
  	info->sechdrs[info->index.info].sh_flags &= ~(unsigned long)SHF_ALLOC;
  	info->sechdrs[info->index.vers].sh_flags &= ~(unsigned long)SHF_ALLOC;
  	return 0;
  }
  
  /*
   * Set up our basic convenience variables (pointers to section headers,
   * search for module section index etc), and do some basic section
   * verification.
   *
   * Return the temporary module pointer (we'll replace it with the final
   * one when we move the module sections around).
   */
  static struct module *setup_load_info(struct load_info *info)
  {
  	unsigned int i;
  	int err;
  	struct module *mod;
  
  	/* Set up the convenience variables */
  	info->sechdrs = (void *)info->hdr + info->hdr->e_shoff;
  	info->secstrings = (void *)info->hdr
  		+ info->sechdrs[info->hdr->e_shstrndx].sh_offset;
  
  	err = rewrite_section_headers(info);
  	if (err)
  		return ERR_PTR(err);
  
  	/* Find internal symbols and strings. */
  	for (i = 1; i < info->hdr->e_shnum; i++) {
  		if (info->sechdrs[i].sh_type == SHT_SYMTAB) {
  			info->index.sym = i;
  			info->index.str = info->sechdrs[i].sh_link;
  			info->strtab = (char *)info->hdr
  				+ info->sechdrs[info->index.str].sh_offset;
  #ifdef CONFIG_KALLSYMS
  			/* Keep symbol and string tables for decoding later. */
  			info->sechdrs[info->index.sym].sh_flags |= SHF_ALLOC;
  			info->sechdrs[info->index.str].sh_flags |= SHF_ALLOC;
  #endif
  			break;
  		}
  	}
  
  	info->index.mod = find_sec(info, ".gnu.linkonce.this_module");
  	if (!info->index.mod) {
  		printk(KERN_WARNING "No module found in object\n");
  		return ERR_PTR(-ENOEXEC);
  	}
  	/* This is temporary: point mod into copy of data. */
  	mod = (void *)info->sechdrs[info->index.mod].sh_addr;
  
  	if (info->index.sym == 0) {
  		printk(KERN_WARNING "%s: module has no symbols (stripped?)\n",
  		       mod->name);
  		return ERR_PTR(-ENOEXEC);
  	}
  
  	info->index.pcpu = find_pcpusec(info);
  
  	/* Check module struct version now, before we try to use module. */
  	if (!check_modstruct_version(info->sechdrs, info->index.vers, mod))
  		return ERR_PTR(-ENOEXEC);
  
  	return mod;
  }
  
  static int check_modinfo(struct module *mod, struct load_info *info)
  {
  	const char *modmagic = get_modinfo(info, "vermagic");
  	int err;
  
  	/* This is allowed: modprobe --force will invalidate it. */
  	if (!modmagic) {
  		err = try_to_force_load(mod, "bad vermagic");
  		if (err)
  			return err;
  	} else if (!same_magic(modmagic, vermagic, info->index.vers)) {
  		printk(KERN_ERR "%s: version magic '%s' should be '%s'\n",
  		       mod->name, modmagic, vermagic);
  		return -ENOEXEC;
  	}
  
  	if (get_modinfo(info, "staging")) {
  		add_taint_module(mod, TAINT_CRAP);
  		printk(KERN_WARNING "%s: module is from the staging directory,"
  		       " the quality is unknown, you have been warned.\n",
  		       mod->name);
  	}
  
  	/* Set up license info based on the info section */
  	set_license(mod, get_modinfo(info, "license"));
  
  	return 0;
  }
  
  static void find_module_sections(struct module *mod, struct load_info *info)
  {
  	mod->kp = section_objs(info, "__param",
  			       sizeof(*mod->kp), &mod->num_kp);
  	mod->syms = section_objs(info, "__ksymtab",
  				 sizeof(*mod->syms), &mod->num_syms);
  	mod->crcs = section_addr(info, "__kcrctab");
  	mod->gpl_syms = section_objs(info, "__ksymtab_gpl",
  				     sizeof(*mod->gpl_syms),
  				     &mod->num_gpl_syms);
  	mod->gpl_crcs = section_addr(info, "__kcrctab_gpl");
  	mod->gpl_future_syms = section_objs(info,
  					    "__ksymtab_gpl_future",
  					    sizeof(*mod->gpl_future_syms),
  					    &mod->num_gpl_future_syms);
  	mod->gpl_future_crcs = section_addr(info, "__kcrctab_gpl_future");
  
  #ifdef CONFIG_UNUSED_SYMBOLS
  	mod->unused_syms = section_objs(info, "__ksymtab_unused",
  					sizeof(*mod->unused_syms),
  					&mod->num_unused_syms);
  	mod->unused_crcs = section_addr(info, "__kcrctab_unused");
  	mod->unused_gpl_syms = section_objs(info, "__ksymtab_unused_gpl",
  					    sizeof(*mod->unused_gpl_syms),
  					    &mod->num_unused_gpl_syms);
  	mod->unused_gpl_crcs = section_addr(info, "__kcrctab_unused_gpl");
  #endif
  #ifdef CONFIG_CONSTRUCTORS
  	mod->ctors = section_objs(info, ".ctors",
  				  sizeof(*mod->ctors), &mod->num_ctors);
  #endif
  
  #ifdef CONFIG_TRACEPOINTS
  	mod->tracepoints_ptrs = section_objs(info, "__tracepoints_ptrs",
  					     sizeof(*mod->tracepoints_ptrs),
  					     &mod->num_tracepoints);
  #endif
  #ifdef HAVE_JUMP_LABEL
  	mod->jump_entries = section_objs(info, "__jump_table",
  					sizeof(*mod->jump_entries),
  					&mod->num_jump_entries);
  #endif
  #ifdef CONFIG_EVENT_TRACING
  	mod->trace_events = section_objs(info, "_ftrace_events",
  					 sizeof(*mod->trace_events),
  					 &mod->num_trace_events);
  	/*
  	 * This section contains pointers to allocated objects in the trace
  	 * code and not scanning it leads to false positives.
  	 */
  	kmemleak_scan_area(mod->trace_events, sizeof(*mod->trace_events) *
  			   mod->num_trace_events, GFP_KERNEL);
  #endif
  #ifdef CONFIG_TRACING
  	mod->trace_bprintk_fmt_start = section_objs(info, "__trace_printk_fmt",
  					 sizeof(*mod->trace_bprintk_fmt_start),
  					 &mod->num_trace_bprintk_fmt);
  	/*
  	 * This section contains pointers to allocated objects in the trace
  	 * code and not scanning it leads to false positives.
  	 */
  	kmemleak_scan_area(mod->trace_bprintk_fmt_start,
  			   sizeof(*mod->trace_bprintk_fmt_start) *
  			   mod->num_trace_bprintk_fmt, GFP_KERNEL);
  #endif
  #ifdef CONFIG_FTRACE_MCOUNT_RECORD
  	/* sechdrs[0].sh_size is always zero */
  	mod->ftrace_callsites = section_objs(info, "__mcount_loc",
  					     sizeof(*mod->ftrace_callsites),
  					     &mod->num_ftrace_callsites);
  #endif
  
  	mod->extable = section_objs(info, "__ex_table",
  				    sizeof(*mod->extable), &mod->num_exentries);
  
  	if (section_addr(info, "__obsparm"))
  		printk(KERN_WARNING "%s: Ignoring obsolete parameters\n",
  		       mod->name);
  
  	info->debug = section_objs(info, "__verbose",
  				   sizeof(*info->debug), &info->num_debug);
  }
  
  static int move_module(struct module *mod, struct load_info *info)
  {
  	int i;
  	void *ptr;
  
  	/* Do the allocs. */
  	ptr = module_alloc_update_bounds(mod->core_size);
  	/*
  	 * The pointer to this block is stored in the module structure
  	 * which is inside the block. Just mark it as not being a
  	 * leak.
  	 */
  	kmemleak_not_leak(ptr);
  	if (!ptr)
  		return -ENOMEM;
  
  	memset(ptr, 0, mod->core_size);
  	mod->module_core = ptr;
  
  	ptr = module_alloc_update_bounds(mod->init_size);
  	/*
  	 * The pointer to this block is stored in the module structure
  	 * which is inside the block. This block doesn't need to be
  	 * scanned as it contains data and code that will be freed
  	 * after the module is initialized.
  	 */
  	kmemleak_ignore(ptr);
  	if (!ptr && mod->init_size) {
  		module_free(mod, mod->module_core);
  		return -ENOMEM;
  	}
  	memset(ptr, 0, mod->init_size);
  	mod->module_init = ptr;
  
  	/* Transfer each section which specifies SHF_ALLOC */
  	DEBUGP("final section addresses:\n");
  	for (i = 0; i < info->hdr->e_shnum; i++) {
  		void *dest;
  		Elf_Shdr *shdr = &info->sechdrs[i];
  
  		if (!(shdr->sh_flags & SHF_ALLOC))
  			continue;
  
  		if (shdr->sh_entsize & INIT_OFFSET_MASK)
  			dest = mod->module_init
  				+ (shdr->sh_entsize & ~INIT_OFFSET_MASK);
  		else
  			dest = mod->module_core + shdr->sh_entsize;
  
  		if (shdr->sh_type != SHT_NOBITS)
  			memcpy(dest, (void *)shdr->sh_addr, shdr->sh_size);
  		/* Update sh_addr to point to copy in image. */
  		shdr->sh_addr = (unsigned long)dest;
  		DEBUGP("\t0x%lx %s\n",
  		       shdr->sh_addr, info->secstrings + shdr->sh_name);
  	}
  
  	return 0;
  }
  
  static int check_module_license_and_versions(struct module *mod)
  {
  	/*
  	 * ndiswrapper is under GPL by itself, but loads proprietary modules.
  	 * Don't use add_taint_module(), as it would prevent ndiswrapper from
  	 * using GPL-only symbols it needs.
  	 */
  	if (strcmp(mod->name, "ndiswrapper") == 0)
  		add_taint(TAINT_PROPRIETARY_MODULE);
  
  	/* driverloader was caught wrongly pretending to be under GPL */
  	if (strcmp(mod->name, "driverloader") == 0)
  		add_taint_module(mod, TAINT_PROPRIETARY_MODULE);
  
  #ifdef CONFIG_MODVERSIONS
  	if ((mod->num_syms && !mod->crcs)
  	    || (mod->num_gpl_syms && !mod->gpl_crcs)
  	    || (mod->num_gpl_future_syms && !mod->gpl_future_crcs)
  #ifdef CONFIG_UNUSED_SYMBOLS
  	    || (mod->num_unused_syms && !mod->unused_crcs)
  	    || (mod->num_unused_gpl_syms && !mod->unused_gpl_crcs)
  #endif
  		) {
  		return try_to_force_load(mod,
  					 "no versions for exported symbols");
  	}
  #endif
  	return 0;
  }
  
  static void flush_module_icache(const struct module *mod)
  {
  	mm_segment_t old_fs;
  
  	/* flush the icache in correct context */
  	old_fs = get_fs();
  	set_fs(KERNEL_DS);
  
  	/*
  	 * Flush the instruction cache, since we've played with text.
  	 * Do it before processing of module parameters, so the module
  	 * can provide parameter accessor functions of its own.
  	 */
  	if (mod->module_init)
  		flush_icache_range((unsigned long)mod->module_init,
  				   (unsigned long)mod->module_init
  				   + mod->init_size);
  	flush_icache_range((unsigned long)mod->module_core,
  			   (unsigned long)mod->module_core + mod->core_size);
  
  	set_fs(old_fs);
  }
  
  static struct module *layout_and_allocate(struct load_info *info)
  {
  	/* Module within temporary copy. */
  	struct module *mod;
  	Elf_Shdr *pcpusec;
  	int err;
  
  	mod = setup_load_info(info);
  	if (IS_ERR(mod))
  		return mod;
  
  	err = check_modinfo(mod, info);
  	if (err)
  		return ERR_PTR(err);
  
  	/* Allow arches to frob section contents and sizes.  */
  	err = module_frob_arch_sections(info->hdr, info->sechdrs,
  					info->secstrings, mod);
  	if (err < 0)
  		goto out;
  
  	pcpusec = &info->sechdrs[info->index.pcpu];
  	if (pcpusec->sh_size) {
  		/* We have a special allocation for this section. */
  		err = percpu_modalloc(mod,
  				      pcpusec->sh_size, pcpusec->sh_addralign);
  		if (err)
  			goto out;
  		pcpusec->sh_flags &= ~(unsigned long)SHF_ALLOC;
  	}
  
  	/* Determine total sizes, and put offsets in sh_entsize.  For now
  	   this is done generically; there doesn't appear to be any
  	   special cases for the architectures. */
  	layout_sections(mod, info);
  
  
  	/* Allocate and move to the final place */
  	err = move_module(mod, info);
  	if (err)
  		goto free_percpu;
  
  	/* Module has been copied to its final place now: return it. */
  	mod = (void *)info->sechdrs[info->index.mod].sh_addr;
  	kmemleak_load_module(mod, info);
  	return mod;
  
  free_percpu:
  	percpu_modfree(mod);
  out:
  	return ERR_PTR(err);
  }
  
  /* mod is no longer valid after this! */
  static void module_deallocate(struct module *mod, struct load_info *info)
  {
  	percpu_modfree(mod);
  	module_free(mod, mod->module_init);
  	module_free(mod, mod->module_core);
  }
  
  static int post_relocation(struct module *mod, const struct load_info *info)
  {
  	/* Sort exception table now relocations are done. */
  	sort_extable(mod->extable, mod->extable + mod->num_exentries);
  
  	/* Copy relocated percpu area over. */
  	percpu_modcopy(mod, (void *)info->sechdrs[info->index.pcpu].sh_addr,
  		       info->sechdrs[info->index.pcpu].sh_size);
  
  	/* Setup kallsyms-specific fields. */
  	add_kallsyms(mod, info);
  
  	/* Arch-specific module finalizing. */
  	return module_finalize(info->hdr, info->sechdrs, mod);
  }
  
  /* Allocate and load the module: note that size of section 0 is always
     zero, and we rely on this for optional sections. */
  static struct module *load_module(void __user *umod,
  				  unsigned long len,
  				  const char __user *uargs)
  {
  	struct load_info info = { NULL, };
  	struct module *mod;
  	long err;
  
  	DEBUGP("load_module: umod=%p, len=%lu, uargs=%p\n",
  	       umod, len, uargs);
  
  	/* Copy in the blobs from userspace, check they are vaguely sane. */
  	err = copy_and_check(&info, umod, len, uargs);
  	if (err)
  		return ERR_PTR(err);
  
  	/* Figure out module layout, and allocate all the memory. */
  	mod = layout_and_allocate(&info);
  	if (IS_ERR(mod)) {
  		err = PTR_ERR(mod);
  		goto free_copy;
  	}
  
  	/* Now module is in final location, initialize linked lists, etc. */
  	err = module_unload_init(mod);
  	if (err)
  		goto free_module;
  
  	/* Now we've got everything in the final locations, we can
  	 * find optional sections. */
  	find_module_sections(mod, &info);
  
  	err = check_module_license_and_versions(mod);
  	if (err)
  		goto free_unload;
  
  	/* Set up MODINFO_ATTR fields */
  	setup_modinfo(mod, &info);
  
  	/* Fix up syms, so that st_value is a pointer to location. */
  	err = simplify_symbols(mod, &info);
  	if (err < 0)
  		goto free_modinfo;
  
  	err = apply_relocations(mod, &info);
  	if (err < 0)
  		goto free_modinfo;
  
  	err = post_relocation(mod, &info);
  	if (err < 0)
  		goto free_modinfo;
  
  	flush_module_icache(mod);
  
  	/* Now copy in args */
  	mod->args = strndup_user(uargs, ~0UL >> 1);
  	if (IS_ERR(mod->args)) {
  		err = PTR_ERR(mod->args);
  		goto free_arch_cleanup;
  	}
  
  	/* Mark state as coming so strong_try_module_get() ignores us. */
  	mod->state = MODULE_STATE_COMING;
  
  	/* Now sew it into the lists so we can get lockdep and oops
  	 * info during argument parsing.  No one should access us, since
  	 * strong_try_module_get() will fail.
  	 * lockdep/oops can run asynchronous, so use the RCU list insertion
  	 * function to insert in a way safe to concurrent readers.
  	 * The mutex protects against concurrent writers.
  	 */
  	mutex_lock(&module_mutex);
  	if (find_module(mod->name)) {
  		err = -EEXIST;
  		goto unlock;
  	}
  
  	/* This has to be done once we're sure module name is unique. */
  	if (!mod->taints || mod->taints == (1U<<TAINT_CRAP))
  		dynamic_debug_setup(info.debug, info.num_debug);
  
  	/* Find duplicate symbols */
  	err = verify_export_symbols(mod);
  	if (err < 0)
  		goto ddebug;
  
  	module_bug_finalize(info.hdr, info.sechdrs, mod);
  	list_add_rcu(&mod->list, &modules);
  	mutex_unlock(&module_mutex);
  
  	/* Module is ready to execute: parsing args may do that. */
  	err = parse_args(mod->name, mod->args, mod->kp, mod->num_kp, NULL);
  	if (err < 0)
  		goto unlink;
  
  	/* Link in to syfs. */
  	err = mod_sysfs_setup(mod, &info, mod->kp, mod->num_kp);
  	if (err < 0)
  		goto unlink;
  
  	/* Get rid of temporary copy. */
  	free_copy(&info);
  
  	/* Done! */
  	trace_module_load(mod);
  	return mod;
  
   unlink:
  	mutex_lock(&module_mutex);
  	/* Unlink carefully: kallsyms could be walking list. */
  	list_del_rcu(&mod->list);
  	module_bug_cleanup(mod);
  
   ddebug:
  	if (!mod->taints || mod->taints == (1U<<TAINT_CRAP))
  		dynamic_debug_remove(info.debug);
   unlock:
  	mutex_unlock(&module_mutex);
  	synchronize_sched();
  	kfree(mod->args);
   free_arch_cleanup:
  	module_arch_cleanup(mod);
   free_modinfo:
  	free_modinfo(mod);
   free_unload:
  	module_unload_free(mod);
   free_module:
  	module_deallocate(mod, &info);
   free_copy:
  	free_copy(&info);
  	return ERR_PTR(err);
  }
  
  /* Call module constructors. */
  static void do_mod_ctors(struct module *mod)
  {
  #ifdef CONFIG_CONSTRUCTORS
  	unsigned long i;
  
  	for (i = 0; i < mod->num_ctors; i++)
  		mod->ctors[i]();
  #endif
  }
  
  /* This is where the real work happens */
  SYSCALL_DEFINE3(init_module, void __user *, umod,
  		unsigned long, len, const char __user *, uargs)
  {
  	struct module *mod;
  	int ret = 0;
  
  	/* Must have permission */
  	if (!capable(CAP_SYS_MODULE) || modules_disabled)
  		return -EPERM;
  
  	/* Do all the hard work */
  	mod = load_module(umod, len, uargs);
  	if (IS_ERR(mod))
  		return PTR_ERR(mod);
  
  	blocking_notifier_call_chain(&module_notify_list,
  			MODULE_STATE_COMING, mod);
  
  	/* Set RO and NX regions for core */
  	set_section_ro_nx(mod->module_core,
  				mod->core_text_size,
  				mod->core_ro_size,
  				mod->core_size);
  
  	/* Set RO and NX regions for init */
  	set_section_ro_nx(mod->module_init,
  				mod->init_text_size,
  				mod->init_ro_size,
  				mod->init_size);
  
  	do_mod_ctors(mod);
  	/* Start the module */
  	if (mod->init != NULL)
  		ret = do_one_initcall(mod->init);
  	if (ret < 0) {
  		/* Init routine failed: abort.  Try to protect us from
                     buggy refcounters. */
  		mod->state = MODULE_STATE_GOING;
  		synchronize_sched();
  		module_put(mod);
  		blocking_notifier_call_chain(&module_notify_list,
  					     MODULE_STATE_GOING, mod);
  		free_module(mod);
  		wake_up(&module_wq);
  		return ret;
  	}
  	if (ret > 0) {
  		printk(KERN_WARNING
  "%s: '%s'->init suspiciously returned %d, it should follow 0/-E convention\n"
  "%s: loading module anyway...\n",
  		       __func__, mod->name, ret,
  		       __func__);
  		dump_stack();
  	}
  
  	/* Now it's a first class citizen!  Wake up anyone waiting for it. */
  	mod->state = MODULE_STATE_LIVE;
  	wake_up(&module_wq);
  	blocking_notifier_call_chain(&module_notify_list,
  				     MODULE_STATE_LIVE, mod);
  
  	/* We need to finish all async code before the module init sequence is done */
  	async_synchronize_full();
  
  	mutex_lock(&module_mutex);
  	/* Drop initial reference. */
  	module_put(mod);
  	trim_init_extable(mod);
  	unset_module_init_ro_nx(mod);
  	module_free(mod, mod->module_init);
  	mod->module_init = NULL;
  	mod->init_size = 0;
  	mod->init_ro_size = 0;
  	mod->init_text_size = 0;
  	mutex_unlock(&module_mutex);
  
  	return 0;
  }
  
  static inline int within(unsigned long addr, void *start, unsigned long size)
  {
  	return ((void *)addr >= start && (void *)addr < start + size);
  }
  
  #ifdef CONFIG_KALLSYMS
  /*
   * This ignores the intensely annoying "mapping symbols" found
   * in ARM ELF files: $a, $t and $d.
   */
  static inline int is_arm_mapping_symbol(const char *str)
  {
  	return str[0] == '$' && strchr("atd", str[1])
  	       && (str[2] == '\0' || str[2] == '.');
  }
  
  static const char *get_ksymbol(struct module *mod,
  			       unsigned long addr,
  			       unsigned long *size,
  			       unsigned long *offset)
  {
  	unsigned int i, best = 0;
  	unsigned long nextval;
  
  	/* At worse, next value is at end of module */
  	if (within_module_init(addr, mod))
  		nextval = (unsigned long)mod->module_init+mod->init_text_size;
  	else
  		nextval = (unsigned long)mod->module_core+mod->core_text_size;
  
  	/* Scan for closest preceding symbol, and next symbol. (ELF
  	   starts real symbols at 1). */
  	for (i = 1; i < mod->num_symtab; i++) {
  		if (mod->symtab[i].st_shndx == SHN_UNDEF)
  			continue;
  
  		/* We ignore unnamed symbols: they're uninformative
  		 * and inserted at a whim. */
  		if (mod->symtab[i].st_value <= addr
  		    && mod->symtab[i].st_value > mod->symtab[best].st_value
  		    && *(mod->strtab + mod->symtab[i].st_name) != '\0'
  		    && !is_arm_mapping_symbol(mod->strtab + mod->symtab[i].st_name))
  			best = i;
  		if (mod->symtab[i].st_value > addr
  		    && mod->symtab[i].st_value < nextval
  		    && *(mod->strtab + mod->symtab[i].st_name) != '\0'
  		    && !is_arm_mapping_symbol(mod->strtab + mod->symtab[i].st_name))
  			nextval = mod->symtab[i].st_value;
  	}
  
  	if (!best)
  		return NULL;
  
  	if (size)
  		*size = nextval - mod->symtab[best].st_value;
  	if (offset)
  		*offset = addr - mod->symtab[best].st_value;
  	return mod->strtab + mod->symtab[best].st_name;
  }
  
  /* For kallsyms to ask for address resolution.  NULL means not found.  Careful
   * not to lock to avoid deadlock on oopses, simply disable preemption. */
  const char *module_address_lookup(unsigned long addr,
  			    unsigned long *size,
  			    unsigned long *offset,
  			    char **modname,
  			    char *namebuf)
  {
  	struct module *mod;
  	const char *ret = NULL;
  
  	preempt_disable();
  	list_for_each_entry_rcu(mod, &modules, list) {
  		if (within_module_init(addr, mod) ||
  		    within_module_core(addr, mod)) {
  			if (modname)
  				*modname = mod->name;
  			ret = get_ksymbol(mod, addr, size, offset);
  			break;
  		}
  	}
  	/* Make a copy in here where it's safe */
  	if (ret) {
  		strncpy(namebuf, ret, KSYM_NAME_LEN - 1);
  		ret = namebuf;
  	}
  	preempt_enable();
  	return ret;
  }
  
  int lookup_module_symbol_name(unsigned long addr, char *symname)
  {
  	struct module *mod;
  
  	preempt_disable();
  	list_for_each_entry_rcu(mod, &modules, list) {
  		if (within_module_init(addr, mod) ||
  		    within_module_core(addr, mod)) {
  			const char *sym;
  
  			sym = get_ksymbol(mod, addr, NULL, NULL);
  			if (!sym)
  				goto out;
  			strlcpy(symname, sym, KSYM_NAME_LEN);
  			preempt_enable();
  			return 0;
  		}
  	}
  out:
  	preempt_enable();
  	return -ERANGE;
  }
  
  int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size,
  			unsigned long *offset, char *modname, char *name)
  {
  	struct module *mod;
  
  	preempt_disable();
  	list_for_each_entry_rcu(mod, &modules, list) {
  		if (within_module_init(addr, mod) ||
  		    within_module_core(addr, mod)) {
  			const char *sym;
  
  			sym = get_ksymbol(mod, addr, size, offset);
  			if (!sym)
  				goto out;
  			if (modname)
  				strlcpy(modname, mod->name, MODULE_NAME_LEN);
  			if (name)
  				strlcpy(name, sym, KSYM_NAME_LEN);
  			preempt_enable();
  			return 0;
  		}
  	}
  out:
  	preempt_enable();
  	return -ERANGE;
  }
  
  int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
  			char *name, char *module_name, int *exported)
  {
  	struct module *mod;
  
  	preempt_disable();
  	list_for_each_entry_rcu(mod, &modules, list) {
  		if (symnum < mod->num_symtab) {
  			*value = mod->symtab[symnum].st_value;
  			*type = mod->symtab[symnum].st_info;
  			strlcpy(name, mod->strtab + mod->symtab[symnum].st_name,
  				KSYM_NAME_LEN);
  			strlcpy(module_name, mod->name, MODULE_NAME_LEN);
  			*exported = is_exported(name, *value, mod);
  			preempt_enable();
  			return 0;
  		}
  		symnum -= mod->num_symtab;
  	}
  	preempt_enable();
  	return -ERANGE;
  }
  
  static unsigned long mod_find_symname(struct module *mod, const char *name)
  {
  	unsigned int i;
  
  	for (i = 0; i < mod->num_symtab; i++)
  		if (strcmp(name, mod->strtab+mod->symtab[i].st_name) == 0 &&
  		    mod->symtab[i].st_info != 'U')
  			return mod->symtab[i].st_value;
  	return 0;
  }
  
  /* Look for this name: can be of form module:name. */
  unsigned long module_kallsyms_lookup_name(const char *name)
  {
  	struct module *mod;
  	char *colon;
  	unsigned long ret = 0;
  
  	/* Don't lock: we're in enough trouble already. */
  	preempt_disable();
  	if ((colon = strchr(name, ':')) != NULL) {
  		*colon = '\0';
  		if ((mod = find_module(name)) != NULL)
  			ret = mod_find_symname(mod, colon+1);
  		*colon = ':';
  	} else {
  		list_for_each_entry_rcu(mod, &modules, list)
  			if ((ret = mod_find_symname(mod, name)) != 0)
  				break;
  	}
  	preempt_enable();
  	return ret;
  }
  
  int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *,
  					     struct module *, unsigned long),
  				   void *data)
  {
  	struct module *mod;
  	unsigned int i;
  	int ret;
  
  	list_for_each_entry(mod, &modules, list) {
  		for (i = 0; i < mod->num_symtab; i++) {
  			ret = fn(data, mod->strtab + mod->symtab[i].st_name,
  				 mod, mod->symtab[i].st_value);
  			if (ret != 0)
  				return ret;
  		}
  	}
  	return 0;
  }
  #endif /* CONFIG_KALLSYMS */
  
  static char *module_flags(struct module *mod, char *buf)
  {
  	int bx = 0;
  
  	if (mod->taints ||
  	    mod->state == MODULE_STATE_GOING ||
  	    mod->state == MODULE_STATE_COMING) {
  		buf[bx++] = '(';
  		if (mod->taints & (1 << TAINT_PROPRIETARY_MODULE))
  			buf[bx++] = 'P';
  		if (mod->taints & (1 << TAINT_FORCED_MODULE))
  			buf[bx++] = 'F';
  		if (mod->taints & (1 << TAINT_CRAP))
  			buf[bx++] = 'C';
  		/*
  		 * TAINT_FORCED_RMMOD: could be added.
  		 * TAINT_UNSAFE_SMP, TAINT_MACHINE_CHECK, TAINT_BAD_PAGE don't
  		 * apply to modules.
  		 */
  
  		/* Show a - for module-is-being-unloaded */
  		if (mod->state == MODULE_STATE_GOING)
  			buf[bx++] = '-';
  		/* Show a + for module-is-being-loaded */
  		if (mod->state == MODULE_STATE_COMING)
  			buf[bx++] = '+';
  		buf[bx++] = ')';
  	}
  	buf[bx] = '\0';
  
  	return buf;
  }
  
  #ifdef CONFIG_PROC_FS
  /* Called by the /proc file system to return a list of modules. */
  static void *m_start(struct seq_file *m, loff_t *pos)
  {
  	mutex_lock(&module_mutex);
  	return seq_list_start(&modules, *pos);
  }
  
  static void *m_next(struct seq_file *m, void *p, loff_t *pos)
  {
  	return seq_list_next(p, &modules, pos);
  }
  
  static void m_stop(struct seq_file *m, void *p)
  {
  	mutex_unlock(&module_mutex);
  }
  
  static int m_show(struct seq_file *m, void *p)
  {
  	struct module *mod = list_entry(p, struct module, list);
  	char buf[8];
  
  	seq_printf(m, "%s %u",
  		   mod->name, mod->init_size + mod->core_size);
  	print_unload_info(m, mod);
  
  	/* Informative for users. */
  	seq_printf(m, " %s",
  		   mod->state == MODULE_STATE_GOING ? "Unloading":
  		   mod->state == MODULE_STATE_COMING ? "Loading":
  		   "Live");
  	/* Used by oprofile and other similar tools. */
  	seq_printf(m, " 0x%pK", mod->module_core);
  
  	/* Taints info */
  	if (mod->taints)
  		seq_printf(m, " %s", module_flags(mod, buf));
  
  	seq_printf(m, "\n");
  	return 0;
  }
  
  /* Format: modulename size refcount deps address
  
     Where refcount is a number or -, and deps is a comma-separated list
     of depends or -.
  */
  static const struct seq_operations modules_op = {
  	.start	= m_start,
  	.next	= m_next,
  	.stop	= m_stop,
  	.show	= m_show
  };
  
  static int modules_open(struct inode *inode, struct file *file)
  {
  	return seq_open(file, &modules_op);
  }
  
  static const struct file_operations proc_modules_operations = {
  	.open		= modules_open,
  	.read		= seq_read,
  	.llseek		= seq_lseek,
  	.release	= seq_release,
  };
  
  static int __init proc_modules_init(void)
  {
  	proc_create("modules", 0, NULL, &proc_modules_operations);
  	return 0;
  }
  module_init(proc_modules_init);
  #endif
  
  /* Given an address, look for it in the module exception tables. */
  const struct exception_table_entry *search_module_extables(unsigned long addr)
  {
  	const struct exception_table_entry *e = NULL;
  	struct module *mod;
  
  	preempt_disable();
  	list_for_each_entry_rcu(mod, &modules, list) {
  		if (mod->num_exentries == 0)
  			continue;
  
  		e = search_extable(mod->extable,
  				   mod->extable + mod->num_exentries - 1,
  				   addr);
  		if (e)
  			break;
  	}
  	preempt_enable();
  
  	/* Now, if we found one, we are running inside it now, hence
  	   we cannot unload the module, hence no refcnt needed. */
  	return e;
  }
  
  /*
   * is_module_address - is this address inside a module?
   * @addr: the address to check.
   *
   * See is_module_text_address() if you simply want to see if the address
   * is code (not data).
   */
  bool is_module_address(unsigned long addr)
  {
  	bool ret;
  
  	preempt_disable();
  	ret = __module_address(addr) != NULL;
  	preempt_enable();
  
  	return ret;
  }
  
  /*
   * __module_address - get the module which contains an address.
   * @addr: the address.
   *
   * Must be called with preempt disabled or module mutex held so that
   * module doesn't get freed during this.
   */
  struct module *__module_address(unsigned long addr)
  {
  	struct module *mod;
  
  	if (addr < module_addr_min || addr > module_addr_max)
  		return NULL;
  
  	list_for_each_entry_rcu(mod, &modules, list)
  		if (within_module_core(addr, mod)
  		    || within_module_init(addr, mod))
  			return mod;
  	return NULL;
  }
  EXPORT_SYMBOL_GPL(__module_address);
  
  /*
   * is_module_text_address - is this address inside module code?
   * @addr: the address to check.
   *
   * See is_module_address() if you simply want to see if the address is
   * anywhere in a module.  See kernel_text_address() for testing if an
   * address corresponds to kernel or module code.
   */
  bool is_module_text_address(unsigned long addr)
  {
  	bool ret;
  
  	preempt_disable();
  	ret = __module_text_address(addr) != NULL;
  	preempt_enable();
  
  	return ret;
  }
  
  /*
   * __module_text_address - get the module whose code contains an address.
   * @addr: the address.
   *
   * Must be called with preempt disabled or module mutex held so that
   * module doesn't get freed during this.
   */
  struct module *__module_text_address(unsigned long addr)
  {
  	struct module *mod = __module_address(addr);
  	if (mod) {
  		/* Make sure it's within the text section. */
  		if (!within(addr, mod->module_init, mod->init_text_size)
  		    && !within(addr, mod->module_core, mod->core_text_size))
  			mod = NULL;
  	}
  	return mod;
  }
  EXPORT_SYMBOL_GPL(__module_text_address);
  
  /* Don't grab lock, we're oopsing. */
  void print_modules(void)
  {
  	struct module *mod;
  	char buf[8];
  
  	printk(KERN_DEFAULT "Modules linked in:");
  	/* Most callers should already have preempt disabled, but make sure */
  	preempt_disable();
  	list_for_each_entry_rcu(mod, &modules, list)
  		printk(" %s%s", mod->name, module_flags(mod, buf));
  	preempt_enable();
  	if (last_unloaded_module[0])
  		printk(" [last unloaded: %s]", last_unloaded_module);
  	printk("\n");
  }
  
  #ifdef CONFIG_MODVERSIONS
  /* Generate the signature for all relevant module structures here.
   * If these change, we don't want to try to parse the module. */
  void module_layout(struct module *mod,
  		   struct modversion_info *ver,
  		   struct kernel_param *kp,
  		   struct kernel_symbol *ks,
  		   struct tracepoint * const *tp)
  {
  }
  EXPORT_SYMBOL(module_layout);
  #endif
  
  #ifdef CONFIG_TRACEPOINTS
  void module_update_tracepoints(void)
  {
  	struct module *mod;
  
  	mutex_lock(&module_mutex);
  	list_for_each_entry(mod, &modules, list)
  		if (!mod->taints)
  			tracepoint_update_probe_range(mod->tracepoints_ptrs,
  				mod->tracepoints_ptrs + mod->num_tracepoints);
  	mutex_unlock(&module_mutex);
  }
  
  /*
   * Returns 0 if current not found.
   * Returns 1 if current found.
   */
  int module_get_iter_tracepoints(struct tracepoint_iter *iter)
  {
  	struct module *iter_mod;
  	int found = 0;
  
  	mutex_lock(&module_mutex);
  	list_for_each_entry(iter_mod, &modules, list) {
  		if (!iter_mod->taints) {
  			/*
  			 * Sorted module list
  			 */
  			if (iter_mod < iter->module)
  				continue;
  			else if (iter_mod > iter->module)
  				iter->tracepoint = NULL;
  			found = tracepoint_get_iter_range(&iter->tracepoint,
  				iter_mod->tracepoints_ptrs,
  				iter_mod->tracepoints_ptrs
  					+ iter_mod->num_tracepoints);
  			if (found) {
  				iter->module = iter_mod;
  				break;
  			}
  		}
  	}
  	mutex_unlock(&module_mutex);
  	return found;
  }
  #endif
  